Spectrum Management Regulations and Procedures Manual

11/17/05 6050.32B TABLE OF CONTENTS Paragraph.................................................................................................................................................Page CHAPTER 1. GENERAL CHAPTER 2. THE RADIO FREQUENCY (RF) SPECTRUM CHAPTER 3. HISTORY, AUTHORITIES AND RESPONSIBILITIES CHAPTER 4. SPECTRUM MANAGEMENT EVALUATION CRITERIA CHAPTER 5. FREQUENCY COORDINATION Page i 6050.32B Table of Contents - continued 11/17/05 CHAPTER 6. TRANSMITTER AUTHORIZATION DOCUMENTS AND CALL LETTER ASSIGNMENTS CHAPTER 7. HIGH FREQUENCY ASSIGNMENT PROCEDURES CHAPTER 8. AIRSPACE EVALUATION 803. Intranet Obstruction Evaluation/Airport Airspace Analysis (IOE/AAA) Web-based System 72 CHAPTER 9. VHF/UHF AIR/GROUND COMMUNICATIONS FREQUENCY ENGINEERING Page ii 11/17/05 Table of Contents - continued 6050.32B CHAPTER 10. NAVIGATIONAL AID (NAVAID) FREQUENCY ENGINEERING CHAPTER 11. LOW/MEDIUM FREQUENCY (L/MF) GROUND NAVIGATIONAL AIDS CHAPTER 12. MICROWAVE DATA/COMMUNICATIONS LINKS FREQUENCY ENGINEERING Page iii 6050.32B Table of Contents - continued 11/17/05 CHAPTER 13. RADAR AND AIR TRAFFIC CONTROL RADAR BEACON SYSTEM (ATCRBS) FREQUENCY ENGINEERING Figure 13-9. ARSR-4 Crystal Oscillator, Stabilized Local Oscillator (STALO) and CHAPTER 14. RADIO FREQUENCY INTERFERENCE Page iv 11/17/05 Table of Contents - continued 6050.32B CHAPTER 15. RADIO FREQUENCY INTERFERENCE MONITORING VANS (RFI VANS) CHAPTER 16. IONIZED AND NONIONIZED RADIATION MEASUREMENTS Page v 6050.32B Table of Contents - continued 11/17/05 CHAPTER 17. LAND MOBILE AND OTHER FM COMMUNICATIONS SYSTEMS FREQUENCY ENGINEERING CHAPTER 18. ELECTRONIC ATTACK (EA) EVALUATIONS Page vi 11/17/05 Table of Contents - continued 6050.32B CHAPTER 19. AUTOMATED ENGINEERING APPENDIX 1. AIRSPACE EVALUATION SECTION 1. BACKGROUND AND PROCEDURES Figure 2. Spurious Emission Level of an FM Broadcast Transmitter Figure 9b. Addenda to FAA Form 74670-1 Notice of Proposed Construction or Page vii

6050.32B Table of Contents - continued 11/17/05 SECTION 2. ENGINEERING PROCEDURES FOR OE CASES FOR FM BROADCAST AND ILS/VOR SECTION 3. ENGINEERING PROCEDURES FOR OBSTRUCTION EVALUATION (OE) CASES OF NON-FM BROADCAST APPENDIX 2. TECHNICAL DATA FOR VHF/UHF COMMUNICATIONS FREQUENCY ENGINEERING Figure 3. High Altitude Enroute and Local Control FPSVs to Approximate Scale and As Figure 6. Comparison of Distance to Horizon From the Same Altitude Between Page viii 06 / 11 /19 Table of Contents - continued 6050.32B CHG 3 Figure 12. Comparison of D/U and Distance Between Facilities With One Tailored APPENDIX 3. NAVAID FREQUENCY ENGINEERING DATA AND PROCEDURES SECTION 1. FREQUENCY/CHANNELIZATION CHART SECTION 2. VOR AND DME/TACAN FREQUENCY ENGINEERING Figure 2b. VOR Service Volumes .............................................................................................. 8a Figure 2c. DME Service Volumes .............................................................................................. 8a Page ix 6050.32B CHG 3 06/11 /1 9 Table of Contents - continued Page x

11/17/05 Table of Contents - continued 6050.32B SECTION 3. ILS AND DME FREQUENCY ENGINEERING Page xi 6050.32B Table of Contents - continued 11/17/05 SECTION 4. CHECKING AN FAA PROPOSED ILS FREQUENCY WITH THE AAM Page xii

11/17/05 Table of Contents - continued 6050.32B SECTION 5. NAVAID RECEIVER TEST FACILITIES FREQUENCY ENGINEERING SECTION 6. ESV FREQUENCY ENGINEERING Page xiii

6050.32B Table of Contents - continued 11/17/05 SECTION 7. MLS AND DME/P FREQUENCY ENGINEERING SECTION 8. LOCAL AREA AUGMENTATION SYSTEM FREQUENCY ENGINEERING st st APPENDIX 4. TECHNICAL DATA FOR VHF/UHF/SHF LINKS Page xiv

11/17/05 Table of Contents - continued 6050.32B APPENDIX 8. SOME PROCEDURES FOR RADAR ANTENNA VERTICAL PATTERN MEASUREMENT BY SOLAR MEANS Page xv (and xvi)

11/17/05 6050.32B CHAPTER 1. GENERAL 1. PURPOSE . This order establishes and describes the spectrum management function in the Federal Aviation Administration (FAA) and delineates policies and procedures for the allocation and engineering of this scarce resource.

2. DISTRIBUTION . This order is distributed to the director level in headquarters, the William J. Hughes Technical Center, and the Mike Monroney Aeronautical Center; to division level in the Technical Operations, Enroute and Oceanic, and Terminal Service Areas; and to all field offices with a supervisory distribution.

3. CANCELLATION. This order cancels and supersedes Order 6050.32A, dated May 1, 1998.

4. EXPLANATION OF CHANGES .

a. Many chapters and appendices have been updated and expanded to reflect, in particular, current FAA policy and ensure appropriate guidance in addressing the broad range of issues related to aeronautical radio frequency spectrum engineering and usage. A number of the more significant changes are highlighted in the following items.

b. Chapter 8 has been updated with new guidance on Obstruction Evaluation notification requirements and automation tools.

c. Chapter 9 has been updated to include guidance regarding the Sustaining Backup Emergency Communications (BUEC) systems, as well as guidance on temporary frequency assignments for, in particular, Air Shows and Fire Fighting.

d. Chapters 14 and 15 have been updated to reflect the current automation and analysis tools to better detect, document, and resolve radio frequency interference (RFI) cases.

e. Chapter 16 has been expanded to address guidelines for radiation hazard measurements and related procedures, as a result of the cancellation on April 22, 1999, of FAA Order 3910.3A, Radiation Health Hazards and Protection, dated October 19, 1983.

f. Chapter 17 has been updated to reflect new frequency allotments, a new channel plan, additional fixed communications systems, and new transmit emission standards.

g. Chapter 19 has been renamed to Automated Engineering (previously Automated Frequency Manager (AFM)) and expanded to more broadly reflect the increased use of automation in satisfying spectrum engineering and analysis functions.

h. Appendix 2 has been updated to reflect new policy changes to the engineering criteria and frequency uses that have been developed for the Air-Ground VHF Communications frequency bands.

i. A new Appendix 3, Section 8 has been added to address Local Area Augmentation System (LAAS) frequency engineering.

Page 1 6050.32B Chapter 1 - continued 11/17/05 5. FORMS . The following forms may be obtained from the FAA Depot through normal supply channels (see the latest edition of Order 1330.3): a. FAA Form 6050-1 , Facility Transmitting Authorization, NSN 0052-00-688-6001; unit of issue: sheet.

b. FAA Form 6050-2 , Transmitter Identification and Operation Authorization, NSN 0052-00-694-9000; unit of issue: sheet.

c. FAA Form 6050-4 , Expanded Service Volume Request, NSN 0052-00-845-6000, unit of issue: set.

6. thru 199. RESERVED.

Page 2 (thru 6)

11/17/05 6050.32B CHAPTER 2. THE RADIO FREQUENCY (RF) SPECTRUM 200. RF SPECTRUM . The RF or electromagnetic spectrum is a finite natural resource used by every country in the world. The internationally used frequency unit is the "Hertz," named for an early pioneer in spectrum research. The Hertz (Hz) is defined as one cycle per second (cps), with further prefixes from the Greek to indicate multipliers. One thousand Hz is defined as 1 kiloHertz (kHz), one million Hz is 1 MegaHertz (MHz) and one billion Hz is 1 GigaHertz (GHz), etc. The electromagnetic spectrum emissions of interest, which are called the radio frequency bands, begin at 10 kHz and end at 300 GHz. Above 300 GHz are visible light, X-rays, gamma rays and other electromagnetic phenomena.

201. MAKEUP OF THE SPECTRUM .

a. By international agreement , the radio spectrum is divided into major bands in frequency decimal multiples of three. The radio spectrum was originally defined in terms of metric system wavelengths. The three multiple came into use because the speed of light and electromagnetic propagation is about 300 million meters per second in free space. The length of a full wavelength is 3 x 10 meters per second (m/s) divided by the frequency in Hz. Noting this frequency/wavelength relationship, a frequency of 3 MHz calculates to 100 meters for a full wavelength.

b. These decade bands of frequencies have international defined names, using common terms. For example, the band of frequencies from 30 kHz to 300 kHz is named Low Frequency (LF) and 300 kHz to 3 MHz is designated Medium Frequency (MF). The bands continue from LF and MF to High (HF), Very High (VHF), Ultra High (UHF) and Super High (SHF) with continuations above and below these ranges. The frequency band names are divided by decimal breaks defined in wavelengths; e.g., 300 kHz is 1000 meters, 3,000 kHz is 100 meters, etc. The United States uses frequency in Hz as the unit for specific administrative tracking of spectrum assignments.

202. SPECTRUM LIMITATION CONSIDERATIONS .

a. Aeronautical safety systems shall be accommodated in aeronautical spectrum which is specifically allocated for the service being satisfied and which is used exclusively by aeronautical safety systems. This ensures protection from non-aeronautical users so that the high levels of integrity and availability required by civil aviation can be met.

b. Congestion within the available spectrum is not the only factor limiting its use. First and primarily are the international agreements and treaties to which the United States is a signatory. These matters are covered in detail in chapter 3. Second is the necessary frequency bandwidth required to convey the transmitted information. Other considerations are spectrum efficiency, propagation, capacity, equipment, economics and interference.

c. International agreements divide the spectrum into bands for either exclusive or shared use by a specific service. The aeronautical service is just one of many defined services which have allocations in specific and limited bands. The aeronautical mobile (R) and aeronautical radionavigation services are directly related to safety of life and property in the air. Therefore, most such bands are allocated exclusively worldwide, where the operations deal directly with operation of aircraft. Ancillary aeronautical services, such as fixed microwave point-to-point systems, are shared with other users.

d. Aeronautical service frequency bands are distributed throughout the radio spectrum.

Page 7 6050.32B Chapter 2 - continued 11/17/05 e. Propagation characteristics play a major role in the limitations on use of the assigned spectrum. LF and MF operate primarily on groundwave and can cover hundreds or thousands of miles day or night quite reliably.

HF uses the ionosphere to reflect signals for great distances around the earth, but are greatly affected by day-to-night and seasonal changes. Beginning around the VHF band, "radio line-of-sight" (RLOS) propagation conditions exist. RLOS extends the visual line-of-sight distance by virtue of the phenomenon that radio waves "bend" near large objects such as the earth. See the Appendix 2 for details. At VHF frequencies and above, radio signals travel in a straight line, modified by the bending of the path due to the RLOS effect. Large metallic or electrically-conducting objects such as steel buildings will attenuate, retard or deflect the signal's path. Signal reflection occurs under some conditions, but it is not considered as a reliable path except where the reflector is a part of the planned path.

f. Technical equipment , particularly its changing style as the state-of-the-art progresses, places severe restrictions on the spectrum engineer in engineering frequencies. For example, the original channel assignments in the VHF communications band were every 200 kHz on the odd frequencies between 118.1 and 126.9 MHz, e.g., 118.1, 118.3, etc. Congestion required narrowing the channels to 100 kHz so frequencies could then be assigned on every decimal frequency, 118.1. 118.2, etc. While technically the number of channels doubled per MHz, all could not be used simply. There were still thousands of 200 kHz channeled transceivers in use. It took years of education and finally agency orders to permit the spectrum engineer full use of the 100 kHz channels.

Subsequent congestion brought further reduction to 50 kHz, then currently to 25 kHz channels, yet protection for a "grandfather" period for older operating equipment always must be given.

g. Economics also has a very big impact on the spectrum engineer's ability to engineer frequencies. As described in subparagraph e, even though revised frequency engineering allocations establishes additional channels, they may not necessarily be able to be used. Whether airline or a private aircraft owner, the ability to meet all the requirements for new equipment to meet technological advances is limited by the ability to pay for it.

h. Interference can be defined as any undesired signal or energy which prohibits or degrades the normal reception of the desired signal. It can be divided into three broad categories; adjacent channel or cochannel radio sources, man-made electrical noise, and natural solar and atmospheric noise.

(1) Adjacent channel or cochannel interference is caused by undesired radio transmissions which the receiving device is unable to separate from the desired transmission. Adjacent channel interference is caused by emitters using nearby channels and occurs because of the inability of the pass band of the victim receiver to discriminate against near-frequency signals. Cochannel interference is caused by emitters using the same frequency which are too close geographically. Proven radio frequency spectrum engineering criteria are used by the spectrum engineer to establish an interference-free assigned frequency.

(2) Man-made interference is the most common and most insidious. The sources are limitless, from "plastic welders," to electric motors of all types, to the incidental and spurious radiation of other transmitters. In addition, there are cases of intentional interference, so-called "bogus" or "phantom" controllers, which FAA must investigate (and prosecute) with the help of other agencies.

(3) Solar and atmospheric noise are outside human control. The sun emits an enormous amount of energy throughout the spectrum, varying in day-to-day intensity and frequency. In frequencies through VHF, solar radiation and atmospheric noise such as lightning and precipitation static are significant. From UHF and above, noise generated internally in equipment is the controlling factor.

Page 8 11/17/05 Chapter 2 - continued 6050.32B (4) Intermodulation is defined as the presence of unwanted signals at the output of a less-than-ideal amplifier resulting from modulation of the components of a complex waveform by each other in a nonlinear system. When two or more signals are applied to a nonlinear device, a mixing or intermodulation action results and signals are produced, having frequencies equal to the sums and differences of the original input signals, among other signals. An otherwise linear device may be driven into nonlinear operation in the presence of strong external signal levels. Although most cases occur in receivers, problems do occur when two or more transmitters start radiating a mixed frequency created when a mix occurs in their final amplifiers, particularly when their antennas are in close proximity. Detailed information will be found in Appendix 2.

(5) Desensitization is the deterioration of reception of a desired signal due to the proximity of a very strong signal. The source of the problem could be of any frequency theoretically, but in practice, communications frequencies usually are effected only by very strong signals below about 1 GHz. The strong signal drives the receiver into non-linear function, desensitizing normal reception as well as generating many unwanted spurious signals within the receiver.

203. thru 299. RESERVED .

Page 9 (thru 16)

11/17/05 6050.32B CHAPTER 3. HISTORY, AUTHORITIES, AND RESPONSIBILITIES 300. GENERAL CONSIDERATIONS . The FAA, as one of the major users of the RF spectrum in the United States, has an important national role in the management of frequencies. In turn, the nation has a major responsibility to the rest of the world in the orderly development and application of the RF spectrum within the international community. To acquaint the reader with the need for effective spectrum management within the agency, this chapter presents an historical background of the development and current national and international administrative authorities and responsibilities. Although it complicates the task, agency spectrum management is bound by many international treaties, as well as the regulatory framework imposed by the dual spectrum control entities in the United States: the Federal Communications Commission (FCC) and the National Telecommunications and Information Administration (NTIA).

301. INTERNATIONAL ORGANIZATIONS .

a. International Telecommunication Union (ITU) .

(1) ITU . The ITU is an arm of the United Nations, with its headquarters in Geneva, Switzerland. It is the fundamental authority for spectrum allocation and management. The ITU currently has a membership of nearly 190 nations, and 650 Sector Members (companies). The organization is one of the oldest international groups in existence. In 1932, it became the successor to the International Telegraph Union that was created in 1865.

(2) ITU Authority . The ITU expresses its authority through the same channels as any other multilateral treaty system. Regulations adopted by this international body must then be ratified further and signed by the various administrations (nations) represented. These regulations are developed at conferences and through negotiation where representatives of member nations formulate recommendations that are presented to the plenary body in session for formal voting action leading to adoption. The adopted policies are then published and include detailed regulations and policies in such areas as terminology, assignment and use of frequencies, band allocations, frequency registration, technical specifications, measures against interference, administrative provisions for stations and distress and safety procedures.

(3) Structure of the Union . An organizational diagram of the ITU, showing major functions of concern to the FAA, is presented in figure 3-1. Some major activities and elements of the Union are as follows: (a) Plenipotentiary Conference . Meeting at intervals of normally not less than 5 years, the Plenipotentiary Conference determines the general policies for fulfilling the purposes of the Union. It reviews the work of the Union and revises the Convention (organization definition) if considered necessary.

(b) World Radiocommunication Conference (WRC) . A WRC is normally convened every three to four years to consider specific radiocommunication matters. A WRC may revise the Radio Regulations, or deal with any radiocommunication matter of worldwide character in accordance with its agenda. The Radio Regulations constitute an international treaty on radiocommunication and cover the use of the radio frequency spectrum by radiocommunication services.

(c) Council . The Council sets the final agenda for a WRC, normally two years before the conference is held.

Page 17 6050.32B Chapter 3 - continued 11/17/05 FIGURE 3-1. PARTIAL ORGANIZATIONAL CHART OF THE ITU Page 18 11/17/05 Chapter 3 - continued 6050.32B (d) Secretary General. The Secretary General is responsible to the Council for external relations, public information and other directed functions. The office provides secretarial services for all conferences and publishes the monthly journal services in several languages for distribution to member nations.

(e) Radiocommunication Sector . The Radiocommunication Sector is one of three major Sectors directly under the authority of the Plenipotentiary Conference and the Council. Its primary functions are to provide for international frequency registration, technical and administrative support to radiocommunication study groups, to provide conference and assembly support and to provide seminars and training.

b. International Civil Aviation Organization (ICAO) . ICAO is to the international scene as FAA is to the national, except that it is only advisory, without authority to enforce its recommendations. Member nations, including the United States, strive for strict adherence to ICAO standards. See figure 3-2. The following is a summary of the ICAO goals: (1) Ensure safe and orderly growth of international aviation throughout the world.

(2) Encourage the arts of aircraft design and operation for peaceful purposes.

(3) Encourage the development of airways , airports and air navigation facilities for international civil aviation.

(4) Meet the needs of the people of the world for safe, regular, efficient and economical air transport.

(5) Prevent economic waste caused by unreasonable competition.

(6) Ensure that rights of contracting nations are respected fully and those nations given equal opportunity.

(7) Promote safety of flight in international air navigation.

(8) Annexes to the ICAO Convention (the "Chicago Convention" which established ICAO) establish international standards and recommended practices (SARPs) for aeronautical requirements such as licensing, airworthiness, security, air traffic, search and rescue, communications, etc. "Standards" are necessary for the safety or regularity of international aviation and "recommended practices" are desirable for the safety or regularity of international aviation.

Page 19 6050.32B Chapter 3 - continued 11/17/05 FIGURE 3-2a. ICAO ASSEMBLY ORGANIZATION CHART FIGURE 3-2b. ICAO SECRETARIAT ORGANIZATION CHART Page 20 11/17/05 Chapter 3 - continued 6050.32B (9) ICAO operates and functions as follows : (a) The Assembly is the sovereign body of ICAO and includes over 180 Contracting States. It meets at least once every three years and handles broad policy issues. Each contracting State has one vote on an issue.

(b) The Council is the governing body of ICAO. It is a resident body comprised of 33 representatives from Member States elected by the Assembly for three-year terms. One of the primary duties of the Council is to adopt SARP's and incorporate these as Annexes to the Convention to achieve international uniformity/standardization and improve air safety, efficiency and regularity of flight. The U.S. has had a representative member on the Council since the beginning of ICAO.

(c) The Air Navigation Commission (ANC) is comprised of 15 qualified technical experts from Member States appointed by the Council. ANC is responsible for examining, coordination and planning all of ICAO's work in the air navigation field and is the principal body concerned with developing SARPs. The ANC forms panels and study groups consisting of outside technical experts to study specific issues and make recommendations to the Council. A technical expert nominated by the U.S. has been a member of the Commission since the beginning of ICAO. This expert has historically had an FAA background.

1. While Headquarters Monitors work on nearly all ICAO Panels, the two which routinely address radio spectrum issues and on which Headquarters participates, are the Aeronautical Mobile Communications Panel (AMCP) and the Global Navigation Satellite System Panel (GNSSP). Working Group F of the AMCP addresses aeronautical radio spectrum issues in general, and develops the ICAO position for WRCs.

2. AMCP studies aeronautical mobile communications issues and develops SARPs for air- ground communications, satellite communications and associated systems. GNSSP is developing the SARPs for the future Global Navigation Satellite System (GNSS).

(d) The Air Transport Committee normally does not address radio spectrum issues. It is comprised of representatives from Member States who are appointed by the Council. Its work includes research and recommendations such as policy guidance on airport and route facility economics and management. It considers air transport issues in global conferences. The Air Transport Committee also forms panels and study groups to process its work.

(e) The Secretariat serves as ICAO's permanent administrative body. The Secretariat staff maintains ICAO documents and its bodies include the Air Navigation Bureau, the Aviation Security Branch and the Technical Assistance Bureau. The Secretariat also administers the Seven Regional ICAO Offices which develop and implement regional aviation initiatives.

302. NATIONAL ORGANIZATIONS - GENERAL . Each member nation of ITU is free to set up its own procedures for authorizing the use of the spectrum within its nation, but consistent with the international table of allocations approved by the last ITU conference. Exceptions may be taken to specific allocations, but a member nation must notify ITU and be subject to conflicting use by other member nations following the allocations.

a. United States International Relations . In the United States, the State Department is responsible for the international representation of the United States in ITU (as well as ICAO) forums, utilizing the full technical and administrative support by all concerned United States agencies. The State Department acts as the ITU voting member. The vote represents the consensus of an extensive NTIA/FCC preparatory process, or when a consensus cannot be reached, the official position of the President. The State Department provides the liaison between the United States and other governments when conflicts arise over application of the ITU Radio Regulations.

Page 21 6050.32B Chapter 3 - continued 11/17/05 b. United States Domestic Structure . The Communications Act of 1934, as amended, established a dual system of control of the spectrum within the United States. The FCC administers all the spectrum assigned to and operated by non-Federal agencies. The Act also specifies that all Federal agencies will have their spectrum needs administered and authorized by a separate agency, currently the NTIA in the Department of Commerce (DOC).

Both agencies, FCC and NTIA, work together to formulate recommendations for national control of the spectrum, as well as supply the Department of State with a consensual position for international conferences.

c. FCC .

(1) Jurisdiction . The FCC has jurisdiction over all non-Federal Government spectrum and spectrum users in the United States. This includes not only broadcast, amateur, industrial, and civil aviation as it applies to licensing the operators and equipment, but also State and municipal government entities as well.

(3) Organization . The Commission is composed of five commissioners, appointed by the President with the advice and consent of the Senate. They serve 5-year staggered terms, so one term expires each year. There can be no more than three commissioners from the same political party. One of the members is appointed by the President to be Chair. A simplified block diagram of FCC organization is found in figure 3-3.

FIGURE 3-3. FEDERAL COMMUNICATIONS COMMISSION Page 22 11/17/05 Chapter 3 - continued 6050.32B d. NTIA .

(1) Jurisdiction . NTIA has authority and responsibility for use of the Federal portion of the spectrum by all Federal agencies, including the DOD and the FAA. It is empowered by the same Act as FCC, but has only the Federal agencies' spectra to administer. NTIA and FCC work closely together, since a good portion of the radio spectrum is shared between Federal and non-Federal users requiring joint action. A block diagram of NTIA is shown in figure 3-4.

(2) Responsibilities . NTIA is responsible for administering that portion of the spectrum allocated to Federal use. It is empowered to authorize Federal agencies, which demonstrate appropriate needs and satisfy specific requirements, to use the spectrum. They can also withdraw that authorization or modify it if required.

NTIA is also bound by the ITU Radio Regulations. FAA's interface with NTIA is normally only at the Washington level.

Page 23 6050.32B Chapter 3 - continued 11/17/05 FIGURE 3-4. NATIONAL TELECOMMUNICATIONS AND INFORMATION ADMINISTRATION Page 24 11/17/05 Chapter 3 - continued 6050.32B (3) Organization. The NTIA Administrator serves as the Special Assistant to the President for Telecommunications. NTIA is currently located in Washington in the DOC. It has no field offices, but in effect does have various "field representatives" in other agencies in the field. For instance, each FAA service area Frequency Management Officer (FMO) is the NTIA's field coordinator for all radar beacons and all radars within certain radar bands. This includes military and non-Federal radars and radar beacons.

(a) Interdepartment Radio Advisory Committee (IRAC) . The IRAC, chaired by the NTIA Deputy Associate Administrator for Domestic Spectrum Management, is one of the most important bodies which interfaces with FAA frequency management. Authorization for all FAA frequencies, including our Land Mobile networks comes through IRAC from NTIA. The IRAC is the working arm of NTIA, composed of 20 members, each an agency of the Federal Government, including FAA. See figure 3-5. FAA participates and provides technical expertise to all subcommittees of the IRAC.

FIGURE 3-5. PARTIAL ORGANIZATION CHART OF THE IRAC (b) Spectrum Planning Subcommittee (SPS) . The SPS carries out IRAC functions which relate to planning for the use of the electromagnetic spectrum. This includes the apportionment of spectrum space for the support of established or anticipated radio services, as well as the apportionment of spectrum space between or among Government and non-Government activities.

(c) Technical Subcommittee (TSC) . The TSC is a subcommittee of IRAC which examines the technical aspects of the use of the electromagnetic spectrum.

(d) Radio Conference Subcommittee (RCS) . The RCS advises the IRAC in those functions relating to preparing for ITU radio conferences. This includes the development of recommended U.S. proposals and positions.

Page 25 6050.32B Chapter 3 - continued 11/17/05 (e) Emergency Planning Subcommittee (EPS). In general, the EPS formulates, guides, and reviews National Security Emergency Preparedness (NSEP) planning for Federal spectrum-dependent systems.

(f) Space Systems Subcommittee (SSS). The SSS, chaired by the NTIA, is responsible to the IRAC for international registration of Government within the ITU forum.

(g) Frequency Assignment Subcommittee (FAS) . The FAS is an IRAC subcommittee, which operates to accomplish all the engineering and coordination for each agency's frequency requests. To facilitate its work, FAS has specialized groups to assist with the enormous task of checking and coordinating every frequency request. The following are the two most important groups to FAA: 1 . Aeronautical Assignment Group (AAG) . The AAG, chaired by the FAA, handles only those frequencies which deal with aeronautical services, both Federal and non-Federal. In so doing, it can tentatively "authorize" frequencies in that service directly to the FMO in the service area after assuring the request meets all IRAC and FAA requirements. Aeronautical frequencies approved by AAG must be approved by the FAS before they become final. The frequency bands under AAG control are shown in figure 3-6.

FIGURE 3-6. AAG CONTROLLED BANDS 190-285 kHz 285-435 kHz* 510-535 kHz* 74.8-75.2 MHz 108-121.9375 MHz inclusive 123.5875-128.8125 MHz inclusive 132.0125-136.0000 MHz inclusive 328.6-335.4 MHz 978-1020 MHz inclusive 1030 MHz 1031-1087 MHz inclusive 1090 MHz 1104-1146 MHz inclusive 1157-1213 MHz inclusive 5000-5250 MHz inclusive *In these bands, only applications for stations in the Aeronautical Radionavigation Service shall be sent to the AAG.

2 . Military Assignment Group (MAG) . The MAG does the same work as AAG, except for the military fixed and mobile communications bands controlled by DOD, 225.000-328.600 MHz and 335.400-399.950 MHz only. FAA requests for use of those frequencies for A/G facilities must go through MAG for initial approval.

(h) Field Coordinators . Because the IRAC lacks expertise in some areas, it needs field assistance in its enormous task of coordinating some operations. As a result, the FAA and the DOD Area Frequency Coordinators (AFC) are tasked with pre-coordination of some portions of the spectrum before the frequency request is submitted to FAS or IRAC.

Page 26 11/17/05 Chapter 3 - continued 6050.32B 1 . FAA Field Coordinators have responsibility for coordinating certain radar frequency bands.

This entails the FMOs having to engineer each new radar or beacon request proposed for operation in their service area, whether civilian test, military, other Federal agency use or FAA. Once the frequency or (in the case of radar beacon) the Pulse Repetition Rate (PRR) has been engineered, it must be given to Technical Operations ATC Spectrum Engineering Services for submission to IRAC through channels. Those bands are shown in figure 3-7.

FIGURE 3-7. BANDS UNDER COORDINATION CONTROL OF FAA FIELD COORDINATORS 1030 MHz Airborne Radar Beacons (Interrogators) 1090 MHz Ground Transponders 1215-1400 MHz Radar (typically en route radar) 2700-2900 MHz Radar (typically terminal and weather radar) 9000-9200 MHz Radar (typically DOD precision approach radar) 2 . DOD AFCs have a similar responsibility but for the telemetry bands 1435-1535 MHz and 2310-2390 MHz. FAA does not use these bands. DOD AFC responsibilities are covered in the NTIA Manual, chapter 8.

(4) Spectrum chart . A wall size detailed graphic representation of the full spectrum is published by NTIA and is available from Technical Operations ATC Spectrum Engineering Services upon request.

e. FAA . The spectrum management function in FAA is totally within the purview of Technical Operations ATC Spectrum Engineering Services. The latest edition of Orders 1100.1, FAA Organization - Policies and Standards, 1100.2, Organization - FAA Headquarters and 1100.5, FAA Organization - Field delineate the specific functions of the office. Figure 3-8 provides a block diagram of Technical Operations ATC Spectrum Engineering Services. Figure 3-9 lists the bands of frequencies with which FAA is concerned.

Page 27 6050.32B Chapter 3 - continued 11/17/05 FIGURE 3-8. TECHNICAL OPERATIONS ATC SPECTRUM ENGINEERING SERVICES Office of ATC Spectrum Engineering Services Program Director Chief Systems Engineer Secretary Management and Program Analyst Spectrum Spectrum Mike Monroney Planning and William J. Hughes Assignment and Aeronautical International Technical Center Engineering Office Center Office Page 28 11/17/05 Chapter 3 - continued 6050.32B FIGURE 3-9. SUMMARY OF FREQUENCY BANDS SUPPORTING AVIATION 9 - 14 kHz OMEGA Navigation System 90 - 110 kHz LORAN C Navigation System * 190 - 435 kHz Nondirectional Beacon * 510 - 535 kHz Nondirectional Beacon 2100 - 28,000 kHz High Frequency Communications * 74.8 - 75.2 MHz NAVAID (Marker Beacon) * 108 - 112 MHz NAVAID (VOR, ILS Localizer) * 112 - 118 MHz NAVAID (VOR, LASS and SCAT-I)) * 118 - 137 MHz VHF Air/Ground Communications 62 - 174 MHz Fixed, mobile Communications 225.0 - 328.6 MHz UHF Air/Ground Communications * 328.6 - 335.4 MHz NAVAID (ILS Glide Slope) 335.4 - 399.9 MHz UHF Air/Ground Communications 406.0 - 406.1 MHz Satellite Emergency Position Indicating Radio Bcn 406.1 - 420.0 MHz Fixed, Mobile Communications 932 - 935 MHz Fixed Communications 941 - 944 MHz Fixed Communications * 960 - 1215 MHz NAVAID (TACAN/DME, etc.)

* 978 MHz ADS-B (UAT) * ** 1030 MHz Radar Beacon, TCAS, Mode S * ** 1090 MHz Radar Beacon, TCAS, Mode S * 1176.45 MHz Planned Global Positioning System (L5) 1227.6 MHz Global Positioning System (L2) ** 1215 - 1390 MHz Air Route Surveillance Radar 1544 - 1545 MHz Emergency Mobile Satellite Communications 1545 - 1559 MHz Aeronautical Mobile Satellite (R) (Downlink) 1559 - 1610 MHz GPS (L1), GLONASS 1645.5 - 1646.5 MHz Emergency Mobile Satellite Communications 1646.6 - 1660.5 MHz Aeronautical Mobile Satellite (R) (Uplink) 1710 - 1850 MHz Low Density Microwave Link ** 2700 - 2900 MHz Airport Surveillance Radar, Weather Radar 2900 - 3000 MHz Weather Radar 3700 - 4200 MHz ANICS (commercial satellite downlink) 4200 - 4400 MHz Airborne Radio altimeter * 5000 - 5250 MHz NAVAID (Microwave Landing System) 5350 - 5470 MHz Airborne Radar and Associated Airborne Beacon 5600 - 5650 MHz Terminal Doppler Weather Radar 5925 - 6425 MHz ANICS (commercial satellite uplink) 7125 - 8500 MHz Radio Communications Link 8750 - 8850 MHz Airborne Doppler Radar ** 9000 - 9200 MHz Military Precision Approach Radar 9300 - 9500 MHz Airborne Radar and Associated Airborne Beacon 11.70 - 12.20 GHz FAATSAT (commercial satellite downlink) 13.25 - 13.40 GHz Airborne Doppler Radar 14.00 - 14.50 GHz FAATSAT (commercial satellite uplink) 14.50 - 15.35 GHz Television (Video) Microwave Link 15.70 - 16.20 GHz Airport Surface Detection Equipment (ASDE III) 21.20 - 23.60 GHz Microwave Link (Multi-use) 24.45 - 24.65 GHz Airport Surface Detection System (ASDE II) * denotes AAG bands engineered by FAA; see NTIA Manual ** denotes those bands for which FAA is national coordinator; see NTIA Manual Page 29 6050.32B Chapter 3 - continued 11/17/05 303. TECHNICAL OPERATIONS ATC SPECTRUM ENGINEERING SERVICES . The following are the major assigned functions for Technical Operations ATC Spectrum Engineering Services: a. Focal point within the FAA for all radio spectrum matters. Develops and executes FAA radio frequency spectrum policy, plans and standards.

b. Engineers, obtains authorizations and protects those frequency assignments necessary to satisfy the requirements of the National Airspace System (NAS).

c. Provides engineering support to service area and field facilities in the resolution and prevention of radio frequency interference to NAS facilities.

d. Manages the classified frequency management data and associated secure computer facility at Headquarters.

e. Performs engineering analysis of frequency assignment proposals by Government agencies, the FCC (for non-Government aviation use), Canada, Mexico and other countries to determine the impact on the NAS, and to preclude radio frequency interference to NAS facilities and services.

f. Represents the agency on the IRAC and other Government and industry spectrum management committees and working groups and Federal advisory committees which address spectrum issues.

g. Serves as the manager of aeronautical frequencies in the United States. Manages and engineers those aeronautical frequencies identified for AAG management and chairs that group. In addition, the NTIA has delegated band coordinator responsibilities to the FAA for radar (1215-1390, 2700-2900 and 9000-9200 MHz bands) and the radar beacon (1030/1090 MHz) systems.

h. Assists in developing the United States' position and inputs for use in various international meetings.

Represents the United States at those ITU and ICAO meetings that require frequency management technical expertise and which address or impact civil aviation matters.

I. Maintains the FAA radio frequency portion of the Federal Government's recovery communications (RCOM) mobilization plans.

j. Conducts engineering studies relating to incorporation of future communications, navigation and surveillance (CNS) systems within assigned portions of the radio spectrum in accordance with the NAS Capital Investment Plan (CIP) and FAA Research, Engineering and Development Plan.

k. Executes the electromagnetic radiation hazard measurement program, both ionizing and non-ionizing, for all FAA equipment and systems.

l. Administers the electromagnetic compatibility portion of the agency's airspace case program.

304. SERVICE AREA FREQUENCY MANAGEMENT OFFICE (FMO) . The following are the major functions assigned to the service area frequency management office: a. Serves as the focal point within the service area for all frequency matters.

b. Investigates and resolves Radio Frequency Interference (RFI) problems.

Page 30 11/17/05 Chapter 3 - continued 6050.32B c. Validates and forwards frequency requirements with specific recommended frequencies to Technical Operations ATC Spectrum Engineering Services.

d. Performs electromagnetic compatibility studies.

e. Performs radiation hazard measurements.

f. Controls and maintains the service area RFI Monitoring Van(s) (RFIM Van).

305. thru 399. RESERVED .

Page 31 (thru 32)

11/17/05 6050.32B CHAPTER 4. SPECTRUM MANAGEMENT EVALUATION CRITERIA 400. GENERAL . This chapter provides the evaluation criteria to measure the field level spectrum management function effectiveness.

401. CRITERIA . The service area spectrum management function evaluations shall be conducted in accordance with the latest edition of Order 1800.14, Airway Facilities Evaluation Program.

402. SUBJECTS OF EVALUATION . The FAA service area spectrum management office performance shall be measured against the following evaluation criteria.

a. Compliance With Standards and Guidelines . Service area spectrum management personnel shall be familiar with and strictly apply as appropriate, ITU, ICAO, FCC, NTIA and FAA published regulations governing frequency matters.

b. Efficiency and Economy .

(1) Personnel functions shall be defined by workload description statements, which accurately define the work performed by the FMO, that accompany the generic position descriptions.

(2) Cross-training shall be accomplished to provide essential coverage of specialized areas.

(3) Economy of personnel and material shall be pursued actively in all operational phases.

c. Spectrum Engineering .

(1) Frequencies shall be engineered properly (prior to formal assignment) with respect to radiation, propagation, emission and power factors, including engineering consideration of protection from potential interference.

(2) The FMO shall be the focal point and provide guidance and expertise in frequency matters to all service area elements.

(3) Guidance shall be provided to the service area’s planning elements in advance of programming actions concerning the spectrum bands to be used, radiated power and emission characteristics of the new facilities and any limitations which appear because of legal or technical restrictions. Likewise, timely spectrum engineering guidance shall be provided to non-Federal entities, other Federal agencies and DOD elements desiring to establish aeronautical systems.

(4) Service area radiating systems shall be evaluated periodically, consistent with established review plans, for compliance with emission and performance standards, with deviations and recommendations reported for correction.

(5) The FMO will coordinate with DOD organizations within their service areas as necessary, to ensure that electronic attack activity (including chaff operations, electronic jamming, etc.), does not impact the NAS.

(6) Airspace cases will be analyzed in such a manner as to ensure that non-Federal users do not cause interference to critical aeronautical facilities.

Page 33 6050.32B Chapter 4 - continued 11/17/05 (7) The FMO shall conduct electromagnetic compatibility studies, as necessary, to determine the effect of proposed systems on current NAS systems.

(8) The FMO should participate in the site selection and installation planning for all new NAS facilities and systems.

(9) The FMO should visit service area centers and TRACONs periodically in order to review requirements for radio spectrum to support NAS operations.

d. Interference resolution .

(1) Frequency interference problems to the NAS from any source shall receive priority attention and be corrected in minimum time.

(2) Close working relationships shall be established with other agency elements in Technical Operations Services, Enroute and Oceanic Services, Terminal Services, Flight Standards (FS), and Airports, as well as local FCC and DOD frequency personnel, to assure rapid correction of interference problems.

(3) Every effort shall be made to terminate or correct an interfering device in lieu of a frequency change to solve a problem.

(4) Appropriate data on incidents shall be entered into the RFI data base and engineering reports shall be prepared, describing problems, their resolution and recommendations regarding action to be taken to preclude recurrence. Copies of the reports shall be furnished to all entities involved and Technical Operations ATC Spectrum Engineering Services.

(5) FMO offices shall have operable mobile and portable electronic interference detection equipment in addition to an RFIM van. Calibration shall be maintained for all critical equipment.

e. Frequency assignment records .

(1) The Government Master File (GMF) shall be kept current.

(2) Frequency utilization shall be reviewed periodically, consistent with established review plans. The reports on the reviews shall include followup actions taken.

(3) Frequency Transmitting Authorizations (FTA) for all FAA transmitters shall be issued by the FMO to the appropriate FAA authority for posting. When visiting a facility, the FMO should review the FTA for posting and accuracy.

(4) Procedures shall be established that use the available automated capabilities to determine quickly the status of all frequency assignment actions.

(5) Filing procedures shall be established to assure rapid retrieval of correspondence and record information.

f. Planning .

(1) Arrangements shall be made to assure that FMOs receive information regarding frequency requirements for new facilities as soon as known, to assure the availability of frequencies.

Page 34 11/17/05 Chapter 4 - continued 6050.32B (2) FMO staff members shall maintain awareness of new system developments and techniques to provide information to planning offices.

(3) Frequency assignment shall be obtained in time to enable installation personnel to order necessary crystals, filters, etc., prior to scheduled installations.

(4) Maintain an awareness of the current status of projects to ensure that frequency records are kept updated.

g. Coordination .

(1) Channels of communication shall be established and maintained with appropriate military representatives and offices, FCC district and monitoring offices, other Federal spectrum users, interference resolution organizations and representatives of non-Federal aviation industry spectrum users.

(2) Other FAA entities, such as Enroute and Oceanic Services, Terminal Services, FS, and non- Fed Coordinator shall be apprised of FMO functions and capabilities.

(3) Coordination requirements for frequency matters in ITU, IRAC, ICAO and FCC regulations and procedures shall be adhered to.

(4) Procedures shall be established and maintained to assure close coordination with adjacent service areas.

h. Radiation Hazard Survey . The FMO is the single point-of-contact in the service area for performing designated radiation hazard measurements, both ionizing and non-ionizing, and is responsible for the definitive measurements of radiation levels. (See Chapter 16).

(1) FMOs shall conduct radiation hazard measurements and prepare reports as required.

(2) Technical Operations ATC Facilities, Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services has overall program management responsibility for environmental hazards, including radiation hazards.

(3) In addition , the following functions are assigned to FMOs through Order 3900.19B: (a) Coordinate and consult with the Industrial Hygiene Program Manager in providing advice and information on matters pertaining to radiation health hazards in FAA operations.

(b) Coordinate with the Industrial Hygiene Program Manager, the Industrial Investigations Program Manager and the Safety and Health Managers in responding promptly to reports of radiation health hazards.

(c) Perform radiation health hazards surveys on new and modified facilities that house equipment, systems or substances capable of producing external ionizing or non-ionizing radiation fields, and others as required.

403. thru 499. RESERVED.

Page 35 (thru 40)

11/17/05 6050.32B CHAPTER 5. FREQUENCY COORDINATION 500. GENERAL .

a. Any frequency assignment MUST be coordinated before it can be processed and authorized. The very nature of radio signal radiation makes it a candidate for interference to another frequency, thus all interested parties must be in agreement before a reliable frequency can be assured. There are five major areas of coordination within the FAA spectrum management function. They are headquarters, field-headquarters, field-external, field-special and field-internal. Each has its own requirements and peculiarities, thus requires separate explanation.

b. As a general policy , only one frequency will be assigned for each individual requirement. For example, only one VHF A/G communications (COMM) frequency will be assigned for each Air Route Traffic Control Center (ARTCC) sector. Frequencies designated as "back-up" or "spare" are not authorized.

501. HEADQUARTERS . All coordination with other Federal agencies, except as discussed in paragraphs 503 through 505, and any with foreign governments, is accomplished only by Technical Operations ATC Spectrum Engineering Services. Numerous coordination procedures have been developed for various frequency usages and are listed in the NTIA Manual of Regulations and Procedures for Federal Radio Frequency Management (NTIA Manual) in paragraph 8.3. This includes the east coast National Radio Quiet Zone (NRQZ).

502. FIELD-HEADQUARTERS . For new programs and systems, Technical Operations ATC Spectrum Engineering Services engineers may do the initial planning, engineering frequency applications. All routine aeronautical COMM, NAV and radar frequencies are engineered in the field and then forwarded to Technical Operations ATC Spectrum Engineering Services prior to being forwarded to Frequency Assignment Subcommittee for approval and eventual inclusion in the Government Master File.

503. FIELD-EXTERNAL . In general, the FMO is urged to form a close working relationship with the field representatives of agencies with whom the FMO will work. A partial list of such agencies and the FMO's responsibilities are as follows: a. Inter-service area Work Force Support . Service areas can better adjust to peak workload conditions by establishing a seamless environment so that service areas can provide support to each other to accomplish functions as peaks occur. This inter-service area support would be provided at the request of the service areas needing the support. Headquarters may, in some cases, provide funding for this support.

b. FCC Field Office . The FMO should become well acquainted with the Engineer in Charge of any FCC Field Office(s) in the FMO's service area. Interference dealing with a non-Federal transmitter will be coordinated with the local FCC. All communications with the local FCC representatives shall go through the regional FMO.

c. DOD AFC . DOD has established AFCs within designated areas of the United States and possessions.

These AFCs represent DOD in their respective areas and have coordination authority over all the military services in their areas. If any DOD AFC has area encompassing any of the FMO's service area, it is imperative that the FMO become well acquainted with the AFC, since all military frequency coordination with FAA within the AFC's area of responsibility will be with the DOD AFC. See NTIA Manual, Chapter 8 and Annex D, for areas of responsibility, contacts, and telephone numbers.

d. Military AFCs . The three main military departments, Army, Navy and Air Force, have their own service coordinators. Each service has a specific area of influence and each area is spelled out in the NTIA Manual, Page 41

6050.32B Chapter 5 – continued 11/17/05 Annex D. Just as with the DOD AFCs, it is important that the FMO become acquainted with these officials whose control areas are within the various service areas.

e. United States Forest Service (USFS) and Bureau of Land Management (BLM) . The person who has frequency coordination responsibility in USFS and the BLM in each service area is one that each FMO should know. In those service areas where forest fires are a problem, requests will be coming in at odd times for VHF COMM frequencies to use for the duration of a fire for communication with water-drop aircraft. Knowing the contact in advance is a great time saver.

f. Search and Rescue (SAR) Groups . There are a large number of SAR groups in the country. Most are state or municipal governments, but a few are citizens groups who are interested in volunteering in searches for lost or downed aircraft. They are the ones who will request temporary frequency authorizations for Emergency Locator Transmitter (ELT) tests.

g. Local Aviation Groups . Local aviation groups are a source of information and frequently come to the FMO for assistance with new frequency requirements. For instance, an airport owner wanting a new Aeronautical Advisory Station (Unicom) frequency will come to the FMO. In addition, these groups have a lot of general information that can benefit the FMO. Included in this category are AOPA, ATA, Civil Air Patrol (CAP) and similar organizations.

h. Other Federal Agencies . It is to the advantage of the FMO to be involved with other Federal agencies in the service area that use the radio spectrum. A good working relationship with other agencies is to the benefit of all. When another Federal agency causes interference to FAA frequencies, contact with the local agency’s technical personnel will bring much faster resolution to the problem than trying to resolve the problem at the national level.

504. FIELD-SPECIAL . The FMO may receive special requests not covered by the normal processes. In such cases, the FMO must take particular care in fulfilling them and should consider all parameters before acting or referring to headquarters. When action is taken, Technical Operations ATC Spectrum Engineering Services shall be notified promptly if the FMO has taken or is contemplating taking action. Some of these actions are: a. ELT Tests . Various SAR groups wish to train their pilots at periodic intervals. To do so, they use an ELT, hidden by one of their group in some relatively remote area to test how long it takes for the pilots to locate it from the air, using whatever direction-finding equipment or techniques they have at their disposal. Refer to subparagraphs (1) and (2) below for the procedure on how to accommodate these requests.

(1) The ELT test frequency is 121.775 MHz, as specified in Advisory Circular 91-44. Training SHALL NOT be conducted on 121.5 MHz or 243.0 MHz.

(2) When a group wishes to conduct ELT training, they shall contact the FMO and provide the following information: (a) Date and time of the test.

(b) Site coordinates .

(c) Organization name and the name of a responsible person in the organization.

(d) A telephone number will be attended during the entire ELT test so that in the event of emergency or unacceptable interference, the test can be terminated quickly.

Page 42 11/17/05 Chapter 5 - continued 6050.32B b. Forest Firefighting Frequencies . USFS and BLM have interagency agreements with FAA for temporary use of A/G COMM frequencies to communicate with water-dropping aircraft during a forest fire. Some states also have firefighting aircraft and may contact FAA. The detailed procedure is left to the individual FMO. It is not uncommon for the firefighting agency to call the FAA duty officer Sunday midnight (or other inconvenient hours) requesting FAA permission to use a VHF COMM frequency. In addition, it is FAA's responsibility to publish the firefighting director's contact frequency in the NOTAM that establishes the temporary flight restrictions (TFR) for firefighting operations. This is to allow media aircraft access to the area to collect news information.

(1) The fire services have proved beyond a doubt that the first 15 minutes of a fire determines whether it can be controlled promptly. The FMO should have a list of available frequencies at ready access, which means that the FMO and staff engineers will have them at home, too. The requesting agency should be advised at the time of authorization to call the FMO or the duty officer as soon as the frequency is no longer needed.

(2) The FMO shall forward a completed frequency assignment to Technical Operations ATC Spectrum Engineering Services, and may notify Technical Operations ATC Spectrum Engineering Services by phone of any frequency use that has been authorized.

c. Fly-ins . Various groups request Terminal Services to provide a temporary control tower for special events of usually one to three days duration. To do that, Terminal Services must be provided with frequencies for the temporary tower or other requirements. On occasion, this might be a UHF frequency, if military aircraft are involved. Mostly, however, the request from Terminal Services will ask for a local control and a ground control frequency. The frequency 123.1 MHz may be used for a tempo control tower when coordinated with SAR, if air safety considerations are met.

(1) Initial contact between the aviation event sponsor and the FAA is normally with either the Flight Standards District Office (FSDO) or Area Director of Terminal Operations for the geographic service area of concern at least 45 days prior to the event. If temporary use of frequencies for control of the event's air traffic is needed, or if the assigned frequencies at the air show's location will be used differently than presently authorized, the Area Director of Terminal Operations for the geographic service area of concern or Flight Standards Field Office (FSFO), as appropriate, will contact the service area FMO for advice, or the sponsor may contact the service area FMO directly.

(2) The aviation event sponsor may have proposed frequencies desired for use, for example, either FCC-controlled frequencies in the 122.8-123.0 MHz band for non-FAA use (UNICOM), (MULTICOM) or specific FAA air traffic control frequencies. The FMO will advise the aviation event sponsor whether the proposed frequencies are acceptable and whether the frequencies being proposed are too congested to allow proper control of the aviation event. If the sponsor has no recommended frequencies or has chosen frequencies which are not acceptable to the FAA, then the FMO will advise the FSFO with a service area coordination number [for an example, see subparagraph (3)] and temporary frequencies, as needed.

(3) A coordination number (for example, GL T030043) will be provided to the event sponsor for each frequency which is coordinated for the event use. The FMO will enter the temporary frequencies into the automated frequency management system to document their use. The frequency assignment will include both start and stop dates for the new assignment.

(4) The FMO will forward a memorandum to the aviation event sponsor noting the coordination and frequencies to be proposed to the FCC for use. A courtesy copy of this document will be provided to Technical Operations ATC Spectrum Engineering Services. An example of such a memorandum is shown in Figure 5-1.

Page 43 6050.32B Chapter 5 – continued 11/17/05 FIGURE 5-1. SAMPLE MEMORANDUM TO AVIATION EVENT SPONSOR Subject: Coordination of Frequencies for Special Aeronautical Events From: Service Area Frequency Management Office To: Aviation Special Event Sponsor As coordinated on (date), this office has no objections to your use of the following frequency for use at (name) air show. The following applies: Frequency Coordinated: Power/Emission: Description of Antenna: Location of Transmitter (include geographical coordinates): Class of Station: Dates/Times to be Used: FAA Service Area Coordination Number: In order to obtain Special Temporary Authority to use this frequency, you must submit a request to the Federal Communications Commission (FCC) via the FCC internet address (currently http://wireless.fcc.gov/), and follow the directions under “online filing”, in order for them to review your application. Please cite the above FAA Service Area Coordination Number on your application documents to expedite FCC processing.

Please contact (name) at FAA (Service Area) Frequency Management Office, (telephone), if you have further questions.

(Signature) cc: Area Director of Terminal Operations; Service Area Non-Fed Coordinator; HQ FAA/Technical Operations ATC Spectrum Engineering Services Page 44 11/17/05 Chapter 5 - continued 6050.32B (5) After coordination with the FAA service area FMO, the sponsor will be expected to submit all required forms and fees to the FCC for a special temporary authority (STA) for use of the coordinated frequencies as required by the FCC rules. The sponsor may do this either by letter, telegram, fax or e-mail.

(6) Upon receipt of the memorandum from the service area, Technical Operations ATC Spectrum Engineering Services will coordinate with the FCC and, in addition, will forward a memorandum to the FCC Licensing Division, Gettysburg, Pennsylvania, noting the FAA service area coordination number and stating that FAA has no objection to the temporary use of the frequencies for the aviation event.

(7) In most cases , the FCC will issue the STA to the sponsor no later than 15 days prior to the event provided that all required forms and fees are received at their office within 30 days of the event.

d. Non-Federal Requirements .

(1) FCC licenses all non-Federal NAVAID and air-to-ground (A/G) COMM facilities . The owner or sponsor of the facility must obtain airspace and frequency approval by FAA while processing the application for a transmitting license through FCC. The following is the order of priority for assigning frequencies to non-Federal facilities after airspace approval has been granted.

(a) Public use airport tower or NAVAID providing Instrument Flight Rules (IFR) service.

(b) Private use airport tower or NAVAID providing IFR service.

(c) Public or private use Visual Flight Rules (VFR) or en route advisory service.

(2) FAA must advise sponsors in subparagraph (c) above that frequency assignments can be taken away from the facility with a one year notice to satisfy a more critical requirement. The sponsor must also be advised that, if frequency changes are required to assign a channel to the facility, the sponsor must reimburse FAA for the cost of the changes.

(3) Non-Federal NAVAID s must be in the NAS. If it is to be private, the applicant shall be advised that a proposed frequency will be engineered if possible. However, since it is not in the NAS, it is subject to withdrawal for a NAS facility, if the frequency is required at a later date. Lastly, the applicant must be advised in writing that if a frequency is engineered, it will be reserved for only one year. After that, it will be withdrawn if not used. Extensions can be given only upon a showing of definite progress in procuring FCC license and equipment delivery. Flight Standards has to concur with the request. If the NAVAID is a Compass Locator (COMLO), the power limit is 25 watts (W). If a VOR or ILS, the power and service volume will be of terminal class.

(4) If a COMM frequency , it also is reserved for only one year. The power limit shall be 10 W.

(5) Equipment shall be FCC type-approved and the applicant shall be so advised.

(6) Licenses for Non-Federal radio navigation aids .

(a) Proponent actions : 1 . The proponent fills out an FAA Form 7460-1 and submits it to the appropriate service area Non-Fed Coordinator.

Page 45 6050.32B Chapter 5 – continued 11/17/05 2 . At the same time , the proponent submits an FCC Form 406 (Application for License) to the FCC Licensing Division at Gettysburg, Pennsylvania.

(b) Service area actions : 1 . Upon receipt of the FAA Form 7460-1 from the proponent, the FAA service area Non-Fed Coordinator will forward the request to Air Traffic Organization System Operations Services.

2 . Air Traffic Organization System Operations Services will initiate an airspace case (as needed) and register the proponent with Aeronautical Information Management (AIM) in System Operations Airspace and AIM.

3 . Air Traffic Organization System Operations Services returns the FAA Form 7460-1 to the service area Non-Fed Coordinator who then submits the form to the service area FMO.

4 . The Service Area FMO engineers the appropriate frequency, prepares a temporary frequency application and forwards it to FAA Headquarters. At the same time, the FMO also extracts the applicable information from the FAA Form 7460-1 to prepare a memorandum to the FCC indicating the status of the proponent's request.

(c) FCC actions : 1. The FCC Licensing Division receives the FCC memorandum, logs it for tracking purposes and forwards it to FCC Headquarters.

2 . FCC Headquarters processes the memorandum and forwards it to FAA Headquarters.

(d) FAA Headquarters actions ; 1. FAA engineers and selects a frequency to satisfy the requirement (based on the temporary frequency assigned by the service area FMO) and forwards the application to NTIA for approval.

2. FAA electronically forwards a copy of the FCC memorandum, with the coordinated frequency, to FCC Headquarters.

3 . When the frequency application is approved by NTIA, the FCC Licensing Division issues the license to the proponent.

e. Electronic Attack (EA) Missions . EA missions are military exercises whereby electromagnetic signals are radiated intentionally to cause interference to other military units being tested for EA defense. See chapter 18 for a detailed discussion.

f. Unusual Request . Unusual requests will be received from time to time, and there is no way to cover them all here. When not covered by specific instructions herein or by headquarters directive, all requests for unusual needs should be telephoned or faxed to Technical Operations ATC Spectrum Engineering Services.

505. FIELD-INTERNAL. All of the foregoing paragraphs in this chapter have dealt mostly with coordination outside the service area office. But coordination within the service area office is as essential as outside. The style of frequency coordination will vary with the service area because of the various configurations of the spectrum management functions. At least the following shall be included: Page 46 11/17/05 Chapter 5 - continued 6050.32B a. Air Traffic . Except for a few land mobile system needs, all frequencies engineered are to meet an air traffic service need. Thus the FMO must coordinate closely with Enroute and Oceanic Services, and Terminal Services, personnel as appropriate. This is not only to meet the current need, but also to be aware of service planning so that efficient spectrum usage in the future may be taken into account.

b. Flight Standards . The same logic applies here, particularly as it relates to NAVAIDs. But if FS needs to change a route or vector, an Expanded Service Volume (ESV) or even a new NAVAID may be required.

Frequent meetings with FS personnel are recommended.

c. New requirements for COMM, NAVAID, and radar facilities . Attendance at program review meetings within the Service Area office and at System Management Offices (SMO) by the FMO is essential to provide as much advance notice as possible of new facilities and programs to permit advanced planning.

d . Adjacent Service Areas . FMOs should coordinate frequently with their counterparts in adjacent service areas. This is particularly important when a planned facility's interference range infringes upon an adjacent service area’s territory. When a frequency request is filed with Technical Operations ATC Spectrum Engineering Services, it is assumed that the FMO has coordinated with any affected adjacent service areas.

506. DOCUMENTATION . The FMO is required to have many sources of documentation in order to effectively coordinate. At least the orders and documents listed in subparagraphs a.- u. below, as applicable, shall be maintained by the FMO.

a. NTIA Manual Of Regulations and Procedures For Federal Radio Frequency Management .

b. FCC Rules and Regulations .

c. ICAO Annex 10 .

d. Government Master File on CD-ROM e. FCC Aeronautical Frequency List (see CFR 47, Part 87 -- Aviation Services).

f. The Daily National Automated Performance Reporting System (NAPRS) data report.

g. Aeronautical Information Manual .

h. ITU Radio Regulations .

i. Military Joint ECM Regulation, CJCSI , Performing Electronic Warfare in the United States and Canada.

j. The latest edition of Order 7610.4 , Special Military Operations.

k. The latest edition of Order 7400.2 , Procedures for Handling Airspace Matters.

m Federal Aviation Act of 1958 , revised April 1981.

n. The latest edition of the Federal Aviation Regulations, Part 77 .

o. The latest edition of Order 7350.6 , Locations Identifier Handbook.

Page 47 6050.32B Chapter 5 – continued 11/17/05 p. The latest edition of Order 1380.40 , Airway Facilities SMO Level Staffing Standard System.

q. Sectional Aeronautical Charts.

r. VFR Terminal Area Charts.

s. Airport Facility Directory.

t. U. S. Terminal Procedures.

u. DOD Flight Information publications .

507. thru 599. RESERVED .

Page 48 (thru 52)

11/17/05 6050.32B CHAPTER 6. TRANSMITTING AUTHORIZATION DOCUMENTS AND CALL LETTER ASSIGNMENTS 600. PURPOSE . This chapter describes the procedures for issuing and posting transmitter authorization documents and the guidelines for assigning call signs to all transmitters.

601. FACILITY TRANSMITTING AUTHORIZATION DOCUMENT (FTA) . All transmitters authorized must have appropriate documentation posted for identification and certification purposes. In FAA, there are two basic forms, a certificate style and a metallic label.

a. For all fixed, base, and land transmitters , the certificate is used. Currently, it is FAA Form 6050-1, Facility Transmitting Authorization. See figure 6-1.

(1) Each facility shall have its own document and its unique document number for file purposes. The number shall consist of two letters identifying the service area, followed by a number. The letters and numbers will remain for that site as long as the site exists. Whenever there are modifications to any assignment at that facility, a new document shall be issued, with an added letter starting with "A." When the assignments are subsequently modified, documents will contain sequential sub-letters, "B," "C," etc. until "Z." After "Z," the letter will start again at "A." The original document shall be posted at the site.

(2) The Automated Frequency Management program (AFM) now in use for frequency request/authorization will generate one FTA for each facility. This program will contain a database of all FTA's issued.

(3) Emission designators for major FAA systems can be found in the appendix.

b. For all mobile transmitters, the identification label, FAA Form 6050-2, Transmitter Identification and Operation Authorization (TIOA), shall be used. For hand held transceivers, either the Form 6050-2 or a smaller equivalent may be used. The call letters of the unit will by typed or inked on it before applying to the transmitter.

Because the metallic labels stick very firmly, any changes in call letters should be accomplished by placing the replacement label directly over the old one. The procedure for assignment of call letters will be covered later. If the unit is transferred to a different organization or shipped to the FAA Depot for exchange and repair, a new identification label will be issued. A sample of both TIOA forms is shown in figure 6-2.

Page 53 6050.32B Chapter 6 – continued 11/17/05 FIGURE 6-1. FAA FORM 6050-1, FACILITY TRANSMITTING AUTHORIZATION (REDUCED) FIGURE 6-2. TIOA FORM FOR MOBILE/PORTABLE/HANDHELD TRANSMITTERS Page 54 11/17/05 Chapter 6 - continued 6050.32B 6 02. REQUESTS FOR FREQUENCY ACTION. Frequency requests from entities within the service area hould be standardized for record purposes. This will assure the FMO receives all the information needed with s e request. A sample service area form is shown in figure 6-3. th RE 6-3. SAMPLE OF TYPICAL SERVICE AREA FREQUENCY REQUEST FORM (REDUCED) FIGU Page 55 6050.32B Chapter 6 – continued 11/17/05 03. CALL LETTER ASSIGNMENT . All transmitters that are in use shall be identified by assigned call 6 tters to meet international requirements, to help users know with whom they are communicating and to identify le ignals in case of interference. s a. Most NAVAIDS are identified in accordance with Order 7350.6, Location Identifier Handbook.

b. Communications facilities are voice identified by facility; e.g., "Denver Tower," "Kansas City Center," tc. e c. HF, VHF, and UHF non-aeronautical service voice transmitters are identified by standardized lpha-numeric call signs. They are the systems described in Chapter 17, Land Mobile and Other FM a ommunications Systems Frequency Engineering. C (1) HF call signs will be issued by Technical Operations ATC Spectrum Engineering Services in ccordance with the standard operating procedure "Procedure for Assigning Call Signs," a policy letter to the a ervice areas. s (2) VHF/UHF Land Mobile call systems shall be managed and issued by the FMO in accordance with aragraphs 604 and 605. p 04. LAND MOBILE CALL SIGNS . Land mobile call signs shall be formulated and assigned in accordance 6 ith subparagraphs a. through e., below. w a. FM Repeater stations call signs shall consist of the prefix "FAA" followed by the repeater's three- or ur-character facility identifier, as shown in the Facility Master File (FMF). fo b. FM Base, Mobile, and Portable transmitters call signs shall consist of the most commonly recognized rea identifier where the station is located, followed by a user identifier issued according to figure 6-4. a c. Stations located at a service area office use the service area identifier. Special organizations will be entified as follows: id Washington Headquarters AHQ Metropolitan Wash. Airports MWA FAA William J. Hughes ACT Technical Center Mike Monroney AAC Aeronautical Center Page 56 11/17/05 Chapter 6 - continued 6050.32B ORGANIZATION IDENTIFIERS FIGURE 6-4. USER Organization Identifier on headquarters, FAA William J. Huges Washingt Technical Center, Mike Monroney Aeronautical Center, Regional Administrator, Regional Communications Control Center 001-099 100-199 Flight Standards 200-299 Civil Aviation Security Aircraft Certification 300-399 Technical Operations Divisions 400-499 Technical Operations SMOs 500-999 d. An alphabetic character following the user identifier will identify the station type thus: B - Base station M - Mobile station .g., dh P - Portable (e han eld) g., ble X - Other (e. porta repeater) or example : DCA 618M would identify a Technical Operations SMO mobile radio at Washington e. F National Airport.

605. STATION IDENTIFICATION REQUIREMENTS . Technically, mobile units communicating with each other or a base station in simplex need not identify if the associated base station identifies. But since much of mobile communication is through a repeater, and identification must be used during that time, it should become standard to use the assigned call sign during every communication. The NTIA Manual paragraph 6.5.2 states, "Each station shall transmit its assigned call sign on each frequency in use at the beginning and end of operation, and at least once an hour. More frequent identification may be made if delay to traffic will not result." Fixed, Land and Mobile (including hand-held) stations must identify this way. Repeater transmitters are presently identified by the voice identification of the stations being repeated. In the future, repeaters will have automatic Morse code or digital identifiers installed which will contain the call assigned by the FMO as described in this chapter.

606. thru 699. RESERVED.

Page 57 (thru 62)

11/17/05 6050.32B CHAPTER 7. HIGH FREQUENCY ASSIGNMENT PROCEDURES 700. GENERAL .

a. HF by definition covers from 3 to 30 MHz. It is that portion of the spectrum that has the potential for providing communications worldwide. For this reason, HF is often referred to as a “poor man’s satellite.” The availability of signal reception anywhere in the world depends on many conditions. The time of day, time of year, time of the 11-year sunspot cycle, and the frequency itself are all determining factors. Up to 30 MHz, the higher the frequency, the further a signal can be received in daytime. But at night, most signals above 15 MHz are RLOS or ground wave propagation. This is due to the nature of the signal as it reflects off one of the various layers of ionosphere from about 50 to around 200 miles above the earth. These reflective layers, known originally as the Kennelly-Heaviside Layers for their discoverers, are now generally referred to as “ionospheric layers.” There are five identified layers that are a consideration in HF radio propagation. See Figure 7-1. Through improvements in technology, many of the factors that need to be considered have been automated (including the development and use of automated HF data link) and HF is becoming a much more reliable means of communication. Due to the increase in reliability and the high cost of satellite service, the demand for HF is increasing.

b. At night , lacking the sun's heating of the various ionospheric layers, most layers will not reflect the higher frequencies. It is common for HF systems to have "day" and "night" frequency pairs or "families of frequencies" spread throughout the HF frequency band so that communications can be established during a variety of propagation conditions. Headquarters has assigned families of five or more frequencies throughout the HF band for use by FAA. One circuit might use an 8 MHz frequency at nighttime and a 16 MHz frequency during the daytime to cover the United States.

(1) The D layer averages 45-55 miles above the earth. Its density, thus its ability to reflect radio signals, varies with the sun's height during the day. The rise and fall of the D layer (sunrise to sunset) determines the lowest usable frequency (LUF) that will support propagation between two selected fixed points at a given time.

This layer is most significant below 5 MHz. This layer permits long-distance reception of AM Broadcast stations at night.

(2) The E layer averages 65-75 miles above the earth. This layer affects mid-range HF frequencies in daylight hours.

(3) The Es layer , usually called the sporadic-E layer, drifts erratically and unpredictably about 70 miles above the earth. It is significant only for frequencies of around 20 MHz and higher.

(4) The F1 layer averages 90-120 miles above the earth. It is also dependent upon the sun for its existence. The F1 layer disintegrates and melds with the F2 layer after sunset.

(5) The F2 layer averages 200 miles above the earth and is the most important layer for long range propagation. It permits reflection of signals that can be received for thousands of miles.

c. The term maximum usable frequency (MUF) refers to the highest frequency that will permit satisfactory propagation of radio signals between two fixed points at a given time. MUF varies diurnally, seasonally and with the sunspot cycle. The HF frequencies that propagate best are between LUF (lowest usable frequency) and MUF, although the frequency for optimum transmission (FOT) is about 20 percent below MUF.

See subparagraphs a. and b., above.

Page 63 6050.32B Chapter 7 – continued 11/17/05 d. A more detailed description of the ionospheric layers can be found in the ARRL Handbook for The Radio Amateur.

FIGURE 7-1. IONOSPHERIC LAYERS ILLUSTRATED Courtesy ARRL Handbook 701. INTERNATIONAL HF REQUIREMENTS . The HF services available to support the NAS international requirements are the Aeronautical Mobile (R) and Fixed services. The HF Aeronautical Mobile (R) service provides A/G communications for flights operating in international airspace beyond the VHF range of air traffic control (ATC) ground stations. The A/G communications in support of the ATC function is provided by Aeronautical Radio, Inc. (ARINC), under contract to FAA. The ground-to-air communications service is a broadcast service, providing meteorological information to enroute aircraft (VOLMET), and is provided by FAA.

Frequency assignments are in accordance with ITU Appendix 27, Frequency Allotment Plan for the Aeronautical Mobile (R) Service and Related Information, from those allotted to Major World Air Route Areas (MWARA), Regional and Domestic Air Route Area (RDARA), and VOLMET, respectively. Aeronautical HF communication is not permitted over the continental U.S. when VHF communications are available, except in times of emergency.

Page 64 11/17/05 Chapter 7 - continued 6050.32B 702. NATIONAL HF REQUIREMENTS . Additional HF services are required to satisfy national (domestic) requirements.

a. HF Aeronautical Mobile (R) service provides A/G communications in the State of Alaska via FAA FSSs. Frequency assignments are made in accordance with ITU, Appendix 27 from those allotted to RDARA and the Annex to the NTIA manual.

b. HF Fixed service provides point-to-point (PTP) communications primarily in support of the National Radio Communications System (NRCS), known internally as Command and Control Communications (C3).

Frequency assignments in this service are made in accordance with the NTIA Manual, Table of Frequency Allocations. See figure 7-2 for authorized NRCS frequencies. Refer to the individual station's FTA for details of the assignment.

FIGURE 7-2. NRCS FREQUENCIES CHNL FREQ NOTES CHNL FREQ NOTES (kHz) (kHz) 00 4055.0 USB (East. U.S.) 18 15851.0 LSB (West. U.S.)

01 4055.0 LSB (West. U.S.) 19 16348.0 USB; LSB 02 4625.0 USB; LSB 20 19410.0 USB (East. U.S.)

03 5860.0 USB 21 19410.0 LSB (West. U.S.)

04 6870.0 USB (West. U.S.) 22 20852.0 USB; LSB 05 6870.0 LSB (East. U.S.) 23 24550.0 USB (West. U.S.)

06 7475.0 USB; LSB 24 24550.0 LSB (East. U.S.)

07 7611.0 USB (East. U.S.) none 3428.0 USB: A/G FIFO use 08 7611.0 LSB (West. U.S.) none 5571.0 USB; A/G FIFO use 09 8125.0 USB (East U.S.) 25 8912.0 USB; A/G FIFO use 10 8125.0 LSB (West. U.S.) 26 11288.0 USB; A/G FIFO use 11 9914.0 USB; LSB 27 13312.0 USB; A/G FIFO use 12 11637.0 USB (East. U.S.) 28 17964.0 USB; A/G FIFO use 13 11637.0 LSB (West. U.S.) none 2866.0 USB; A/G Alaska only 14 13457.0 USB (West. U.S.) none 3449.0 USB; A/G Alaska only 15 13457.0 LSB (East. U.S.) none 8855.0 USB; A/G Alaska only 16 13630.0 USB; LSB none 11375.0 USB; A/G Alaska only 17 15851.0 USB (East. U.S.)

NOTES: 1. USB - upper sideband operation 2. LSB - lower sideband operation 3. Eastern U.S. is defined as East of the Mississippi River 4. Western U.S. is defined as West of the Mississippi River Page 65 6050.32B Chapter 7 – continued 11/17/05 703. HF ENGINEERING . For new HF requirements, Technical Operations ATC Spectrum Engineering Services normally does the HF engineering. Service areas may be asked to provide the following information to process the frequency assignment.

a. Station Class (STC) b. Emission (EMS) c. Power (PWR) d. Transmit/Receive State (XSC/RSC) e. Transmit/Receive Antenna Location (XAL/RAL) f. Transmit/Receive Antenna Latitude (XLA/RLA) g. Transmit/Receive Antenna Longitude (XLG/RLG) h. Transmit/Receive Antenna Dimensions (XAD/RAD - gain only) i. Transmit Azimuth (XAZ) j. Authorized Area of Operation (*RAD) k. Number of Stations and System Name/Identifier (*NRM) l. FACID Sort 704 . ASSIGNED VS. WINDOW FREQUENCY. The Frequency Transmit Authorization (FTA) that is issued by the service area should contain the window frequency (the frequency that is dialed into the radio) for each HF frequency assignment that is to support a single side band operation. The assigned frequency is required to reflect the center of the occupied bandwidth, but for a single sideband assignment, this is not the frequency that the radio is tuned to. For an Upper Side Band (USB) assignment, the window frequency is equal to the assigned frequency minus one-half of the assigned bandwidth (e.g. the window frequency for an USB frequency assignment of 5572.4 kHz with a 2.8 kHz bandwidth is 5572.4 – 1.4 = 5571 kHz. Therefore, when the radio is tuned to 5571 kHz the transmitted information is contained between 5571 kHz and 5573.8 kHz with the center of the bandwidth -5572.4 kHz - being the assigned frequency. For a Lower Side Band (LSB) frequency assignment, the window frequency would be the assigned frequency plus one-half of the assigned bandwidth.

705. PROPAGATION AND CIRCUIT RELIABILITY . There are several computer models that will reasonably predict HF radio signal propagation via ionospheric sky wave paths. These models have many parameters, but are mainly predicated on sunspot activity.

706. SUNSPOT NUMBERS . Sunspot numbers are the number of sunspots observed over a specific period of the approximate 11-year cycle. The National Institute of Standards and Technology (NIST) observation group determines the level of effect. The HF MUF varies due to many factors (see paragraph 700), including sunspot activity. The more sunspot activity, the more the ionosphere is ionized, the denser the layer and the higher the MUF. The reverse is true as sunspot activity decreases. A plotted graph of observed sunspots for 1749-1996 is shown in figure 7-3.

Page 66 11/17/05 Chapter 7 - continued 6050.32B 707. SOLAR FLARE/STORM REPORTING PROCEDURES . The NIST provides solar flare alerts to FAA through Technical Operations ATC Spectrum Engineering Services, who in turn, passes them to FMOs.

Although the heaviest effect is upon HF, VHF as well as hard-wired data circuits are affected due to the increased earth magnetic currents. The usual VHF effect on communications is a squelch break, followed by a "hissing" noise.

FIGURE 7-3. MONTHLY SUNSPOT NUMBERS JAN 1749 - APR 1996 708. thru 799. RESERVED .

Page 67 (thru 70) 6050.32B Chapter 8 - continued 11/17/05 (2) Any changes or modifications to radio frequency systems, when specified in the original FAA determination, including: (a) Change in the authorized frequency.

(b) Addition of new frequencies.

(c) Increase in effective radiated power (ERP) equal to or greater than 3 decibels (db).

(d) Modification of radiating elements such as: 1 . Antenna mounting location(s) if increased 100 feet or more, irrespective of whether the overall height is increased.

2 . Changes in antenna specifications (including gain, beam-width, polarization, pattern).

3 . Change in antenna azimuth/bearing (if directional antenna) .

802. Title 49, Section 44718 . By regulation or order when necessary, the Secretary of Transportation shall require a person to give adequate public notice, in the form and way the Secretary prescribes, of the construction of any structure or landfill that may result in an obstruction of the navigable airspace or an interference with air navigation facilities and equipment or navigable airspace. An aeronautical study shall be conducted to determine the extent of the adverse impact, if any, on the safe and efficient use of such airspace, facilities or equipment. It also provides for aeronautical studies regarding an existing object. The service area FMO shall evaluate these cases for hazardous electromagnetic effect in the same manner described in paragraph 801a. Aeronautical studies will be handled directly with the proponent by System Operations Services, who will keep Technical Operations ATC Spectrum Engineering Services informed of all action.

803. INTRANET OBSTRUCTION EVALUATION/AIRPORT AIRSPACE ANALYSIS (iOE/AAA) WEB-BASED SYSTEM . The iOE/AAA is a national, web-enabled application that allows data sharing, and communication between and among FAA service areas and employees. The iOE/AAA system replaces the previous procedure in determining the potential effects of various types of man-made structures in the NAS.

Commercial and/or government entities submit construction plans to the FAA regarding new or existing structures obstructions. Obstruction Evaluation Services personnel will then input the data into the iOE/AAA system to evaluate the potential effects to the NAS, based on criteria indicated in FAA Order 7400.2 (“Procedures for Handling Airspace Matters”). FMOs shall use the iOE/AAA system to track each case study which is routed to them through the system, and will provide an EMI and obstruction analysis response in a timely manner.

804. WASHINGTON HEADQUARTERS REVIEWS . The sponsor of any proposed construction or alteration, or any person who stated a substantive aeronautical comment on a proposal in an aeronautical study, may petition the Administrator for a discretionary review of a determination, revision or extension of a determination issued by the service area Obstacle Evaluation Services organization. The authority to grant a review is delegated to System Operations Services. Such petitions are processed and coordinated by the Airspace and Rules Division within System Operations Services. Once granted, discretionary review is conducted by the various Washington Headquarters services in the same manner as the original service area evaluation. Based upon review, analysis and evaluation of the service area’s report of the aeronautical study, briefs, and related submissions by any interested party, the Airspace and Rules Division within System Operations Services prepares a notice affirming, revising, or reversing the original determination for the signature of the Vice-President for System Operations Services.

Page 72 11/17/05 Chapter 8 - continued 6050.32B 805. ELECTROMAGNETIC EVALUATION . The electromagnetic evaluation of a proposed construction or alteration to any man-made structure or facility must be detailed and consistent. Particular attention should be given to high power AM, FM, and TV broadcast proponents, as well as, several other frequency bands, administered by the FCC, that are adjacent to or co-channel with FAA authorized frequencies.

a. The evaluation should begin by gathering all pertinent data required. Through the use of various programs and on-line databases available in the AFM, a listing of all ground aeronautical receivers and transmitters and all commercial broadcast transmitters should be compiled. This list must include frequency, geographic coordinates, emitter effective radiated power (ERP), and elevations. Consideration must be given to overall terrain height, antenna height, and the proximity of any existing commercial transmitters.

b. When plotting the chart , locations of Instrument Landing System (ILS) Frequency Protected Service Volumes (FPSV), ESVs, Markers, VHF Omnidirectional Radio Range (VOR), air-to-ground communications (COMM) and surveillance facilities should be noted. In some cases, facilities within a 30 nautical mile (nmi) radius or more of the proposed site may need to be accounted for.

c. An intermodulation (IM) study utilizing the frequencies compiled is the next step. The study should include at least third order calculations. If hazardous intermodulation products result, the Venn diagram procedure detailed in Appendix 1of this order must be used to determine where it exists for all situations except those involving FM broadcast stations to ILS localizers and VORs. The predicted area of intermodulation must fall in the FPSV for a hazard to exist.

d. Brute force for COMM facilities is also calculated using the Venn diagram method. If an aircraft enters this area, the broadband radio frequency (RF) section of the receiver will be driven into non-linearity regardless of transmitted frequency and desensitization will result.

e. The Airspace Analysis Model (AAM) will be used to evaluate the effects of FM broadcast signals on ILS localizer, VOR and COMM signals received by airborne receivers, as well as by ground receivers in the case of COMM. This includes intermodulation, receiver front-end overload and adjacent channel interference.

f. Signal levels at the input of FAA ground receivers should be calculated for both out-of-band and in-band (spurious) signals.

g. A very important part of this entire evaluation is a vertical profile plot of the proposed site and affected facilities. In many cases, it will be necessary for the FMO to obtain the antenna radiation patterns (horizontal and vertical) from the proponent. All calculations are based on an isotropic radiator. Use of the actual antenna radiation pattern provides a more realistic evaluation.

h. The complete and detailed procedure along with several examples of an airspace evaluation is contained in Appendix 3 of this order.

806. The AAM was designed to assist the FMO in determining the effects of various radio frequency emitters on aircraft navigation and communications facilities. The model determines the effects of FM broadcast stations on ILS localizer and VOR signals. It allows the selection of a proponent FM station to provide a complete compatibility analysis between the proponent and any selected localizer within 30 nmi of the proponent. It is available for download at the Technical Operations ATC Spectrum Engineering Services website.

a. The AAM computes the boundaries of a three-dimensional service volume for the specified facility. It then generates a test grid inside the service volume at specified horizontal and vertical increments. The field strength for the proponent station is computed at each point on this grid and compared to threshold criteria that have been shown in bench measurements to cause brute force interference in typical receivers. All possible Page 73 6050.32B Chapter 8 - continued 11/17/05 2- and 3-frequency third order IM products involving the proponent and other FM transmitters are computed and the combined field strength of the stations contributing to each product is compared to other threshold criteria.

b. The output of the AAM is a series of plot files of predicted interference points within the designated service volumes. The files may be plotted to a terminal screen, a printer or a plotter. The AAM will also indicate if no interference potential exists. A complete technical description of the AAM is available when the AAM is downloaded for use.

807. DETERMINATIONS . After the engineering evaluation has been performed, it is necessary to determine whether the predicted interference (if any) is a hazard to air navigation.

a. In a 1985 letter from the Chairman of the FCC to the Administrator of the FAA, it was agreed that in certain situations where there is insufficient scientific information upon which to make a conclusive determination, that certain limiting conditions would be added directly to new or modified station authorizations.

These limiting conditions that are set forth in the "conditional statement" are as follows: Upon receipt of notification from the Federal Communications Commission that harmful interference is being caused by the licensee's (permittee's) transmitter, the licensee (permittee) shall either immediately reduce the power to the point of no interference, cease operation or take such immediate corrective action as is necessary to eliminate the harmful interference. This condition expires after 1 year of interference- free operation .

b. This includes the following situations : (1) VHF-TV broadcast proponents that appear to be a hazard based on the current electromagnetic interference prediction data and methods.

(2) FM broadcast proponents proposing to relocate and/or modify an existing FM station resulting in an equal or lesser interference problem than presently exists. This can include a change in location, power, frequency, antenna height or antenna type.

(3) Interference is predicted in an area inside the service volume where an aircraft cannot possibly fly due to terrain, physical obstructions, and/or effects of EMI.

808. NON-BROADCAST EVALUATIONS . There are special considerations given to certain non-broadcast transmitters. These procedures are covered under a joint public notice issued by FAA and FCC and a joint agency policy for Technical Operations Services and Air Traffic Organization System Operations Services. The public notice is quoted verbatim as subparagraph a, below. The agency policy is summarized in subparagraph b, below.

a. Joint FAA/FCC public notice : The Federal Aviation Administration (FAA) and the Federal Communications Commission (FCC) have reached an agreement to simplify the handling of electromagnetic interference (EMI) issues with respect to AM broadcast stations, fixed microwave transmitters, and cellular radiotelephone fixed transmitters. The FAA's concern in this area arises from the possibility that such transmitters might be installed too close to remotely controlled aeronautical receivers so as to disrupt air traffic control communications and navigational aids.

It has been agreed that the FAA will not issue a hazard determination to those applicants for licenses involving cellular fixed transmitters, fixed microwave transmitter, or AM broadcast transmitters that invite potential EMI, nor, will the FAA request the applicants to use filtering Page 74 11/17/05 Chapter 8 - continued 6050.32B beyond what is normally required by FCC rules. Rather, the FAA will include the following language in a Determination of No Hazard, assuming that physical obstruction is not an issue.

FAA facilities critical to aviation safety are located (distance) from your proposed transmitter site. You may cause harmful interference to these facilities if your equipment meets only minimum FCC standards for spurious emissions. Before you begin any transmission from your facility, contact (name and phone number of local FAA contact) to arrange procedures to verify that no interference is caused.

FCC requirements in: 47 CFR 73.44 (c) (in the case of AM broadcast stations) 47 CFR 22.907 (c) (in the case of fixed cellular transmitters) 47 CFR 21.106 (c) (in the case of common carrier fixed microwave transmitters) 47 CFR 74.23 (a) (in the case of broadcast auxiliary transmitters) 47 CFR 94.71 (d) (in the case of operational fixed service transmitters) indicate that the licensees may need to employ extra filtering or take other measures if their transmissions disrupt other services. The commission requires its licensees to cooperate fully with other Federal agencies (users in other services) in this case the FAA, to eliminate any harmful interference covered by the above requirements.

This agreement does not affect the requirement of an FCC applicant to notify the FAA of proposed construction or modification of towers under existing FAA and FCC rules. Facilities located near airports raise concerns about possible interference to aircraft and will be handled under existing procedures.

This agreement should speed the authorization of service for licensees in the above categories.

Both agencies agree that this special case of potential interference to ground based receivers from transmitters at widely differing frequencies can be adequately handled by requiring the licensee (applicant) to shut down if EMI is present due to the use of the transmitter.

b. The policy for use of the new statement for AM broadcast, cellular, PCS, and microwave transmitters which are a potential for electromagnetic interference (EMI) is as follows: (1) The FMO shall not recommend that a Determination of Hazard be issued when an AM broadcast, cellular, PCS, or microwave transmitter evaluation indicates the possibility of EMI to an FAA facility.

(2) The current procedures for determining whether the proposed facility will exceed the limits of -4 dBm for out-of-band or -104 dBm for in-band shall be used for evaluation.

(3) If no problem is predicted , the FMO shall so notify the service area Obstacle Evaluation Services entity involved.

(4) If a problem is predicted, instead of either recommending a hazard be written or telling the proponent that additional attenuation will be required, Obstacle Evaluation Services will be provided with the name of the service area FMO whom the proponent must contact to arrange procedures to verify that no interference is caused. This initial verification is done during the CP phase of the FCC licensing process. FCC rules require that during this period, all interference must be eliminated before the applicant can receive a transmitting license.

Page 75 6050.32B Chapter 8 - continued 11/17/05 (5) Upon notification by the propo n ent of the intent to turn on a new transmitter, the service area FMO will contact the System Management Office that is responsible for the facility where the problem has been predicted. The following is the required procedure: (a) The System Management Office will coordinate the turn-on for testing of the new facility with the proponent to ensure that all FAA personnel are aware of the existence of the new potential for interference and make whatever arrangements they feel are necessary to adequately monitor any suspected EMI to FAA equipment.

(b) These arrangements can include having a technician at the site to monitor the equipment, advising Obstacle Evaluation Services of the potential for interference and to be aware of it, or even simply noting the new facility in case interference is reported in normal day-to-day operations.

(c) If interference is detected , the System Management Office will immediately notify the proponent, who will shut down the interfering transmitter. The System Management Office will also notify the service area FMO who in turn will contact the local FCC office.

(d) The FCC will , at this point, use their own existing procedures to bring the proponent into compliance with the applicable FCC requirements.

(e) Only in the rarest situations would a proposal be submitted for one of these services at a location that could endanger FAA facilities. Such a condition (such as a high power AM BC transmitter located in close proximity to an airport or navigational aid) would be so obvious to the reviewing official that it would be accorded special attention beyond the requirements of the notice.

809. thru 899. RESERVED.

Page 76 (thru 80)

11/17/05 6050.32B CHAPTER 9. VHF/UHF AIR/GROUND COMMUNICATIONS FREQUENCY ENGINEERING 900. PURPOSE . The purpose of this chapter is to present an overview of the frequency engineering necessary for A/G communications in the VHF and UHF bands. The detailed frequency engineering for this function is found in Appendix 2.

901. COMMUNICATIONS FREQUENCY ALLOCATIONS . All voice communications for ATC utilizes AM in the bands: 118.000 - 136.975 MHz* 225.000 - 328.600 MHz# 335.400 - 400.000 MHz# * Portions are not available to FAA. See Appendix 2.

# Only some frequencies are usable by FAA air traffic control communications (pilot-to-controller) with military aircraft.

902. BASIC PRINCIPLES OF COMMUNICATIONS FREQUENCY ENGINEERING . Due to the fixed number of frequencies available for communications facilities, each communications frequency is reused as often as possible throughout the country. Communications frequency engineering provides an interference-free environment for each facility within its FPSV. There are several different functions for communications and each has its own FPSV, defined in the appendix. Communications frequency engineering involves three analysis disciplines: intersite (cochannel), adjacent channel and cosite.

a. Intersite analysis is necessary to prevent radio frequency interference (RFI) between facilities providing service on the same frequency at different geographic locations. The basic factors considered in intersite analysis are the Radio Line of Sight (RLOS) and the ratio between Desired (D) and Undesired (U) signal levels (D/U), as seen at the airborne receiver input. As discussed in Appendix 2, the ratio of the desired and undesired signals can be calculated using path loss between the desired signal source and the undesired signal source at the critical point on the FPSVs associated with the two facilities being analyzed. All cochannel communications frequency assignments shall be engineered to meet a D/U distance ratio of 5:1 (a signal D/U ratio of 14 dB), and all cochannel broadcast transmitters shall be beyond RLOS to any point within the FPSV.

b. Adjacent channel analysis is necessary to prevent RFI resulting from the close location of two FPSVs with frequency separations of only 25 kHz. Since some frequency separation does exist, path loss is not as critical as in the intersite analysis above. The basic method is to separate FPSVs so that they do not overlap, plus a small additional protective distance (see the appendix for a complete discussion). For adjacent channels separated by 25 kHz, the FPSVs shall be geographically separated by a minimum of 0.6 nmi horizontally or 7,000 feet vertically.

For adjacent channels separated by 50 kHz or more, no geographic separation shall be required between the FPSVs.

c. Cosite analysis is necessary to prevent RFI resulting from the interaction of transmitter and receivers at or near the same site, which may be far removed in frequency. These sources can be FAA equipment in the same building, or high power or broad-spectrum emissions such as AM/FM/TV broadcast stations from a few miles away. Cosite RFI includes intermodulation, spurious emission, cross-modulation, harmonic, image, and overload interference. A discussion of cosite interference is found in Appendix 2.

Page 81 6050.32B Chapter 9 - continued 11/17/05 903. SPECIAL ISSUES TO BE CONSIDERED .

a. Ground transmitter power is normally at a level of 10 watts (W). The need for higher power must be justified in the FMO’s application for a frequency approval .

b. UHF coverage is less than VHF, even for the same power. When the service radius exceeds 100 nmi, power available (limits of coverage) curves must be checked carefully.

c. Aircraft transmitter power differs between aircraft. For practical frequency engineering, all aircraft are assumed to have the same output Effective Isotropic Radiated Power (EIRP) as that of the ground transmitter.

d. FM and TV broadcast interference , primarily from receiver overload (desensitization) is an increasing concern. The FMO shall carefully check the proximity for the presence of such transmitters during frequency engineering process. This is discussed in detail in the appendix.

e. Slant range is the actual distance between the ground transmitter and an aircraft at any critical point, with the radial distance and the altitude of the aircraft each forming a leg of a triangle. The hypotenuse is the actual distance, or slant range. However, because of the shape of most FPSVs, there is negligible difference between the slant range and the ground radial distance, so the service radius is always considered as a ground radial.

f. Antenna coverage is affected by lobing of antenna radiation. Within limits, the lower the VHF or UHF antenna with respect to ground level, the better the overall coverage. This is very evident in Appendix 2.

g. At some "problem" sites , e.g., where there is limited real estate for adequate antenna separation or other constraints, FMOs may be required to consider multicouplers and/or combiners to prevent frequency interference.

The following policy addresses the use of multicouplers and/or combiners.

(1) Technical Operations ATC Spectrum Engineering Services will manage the overall program for requirements and budgetary purposes.

(2) FMOs will validate the requirements for multicoupler/combiners at sites within their service areas in coordination with the concerned Regional Associate Program Managers (RAPM).

(3) FMOs must carefully specify requirements for multicouplers and combiners. Whereas multicouplers are somewhat flexible in their potential for retuning to meet changing requirements, the combiner can tune only within a very narrow range of operating frequencies.

(4) FMOs shall note use of multicouplers/combiners in the GMF remarks section using the appropriate format.

904. AUTOMATIC TERMINAL INFORMATION SERVICE (ATIS) VOICE OUTLET ASSIGNMENT CRITERIA. The following criteria will be used to the maximum extent possible in selecting ATIS voice outlets: a. Priority for selecting a frequency to support ATIS broadcasts: (1) VOR or VOR with tactical air navigation capability (VORTAC), except if they are Doppler-type, provided the VOR or VORTAC is located within three nautical miles of the airport. This only applies to those VORs that do not currently provide other broadcast signals such as Enroute Flight Advisory System (EFAS).

(2) VOR test facility (VOT) for departure ATIS only.

Page 82 11/17/05 Chapter 9 - continued 6050.32B (3) A 25 kHz discrete VHF air-ground frequency (for service to the military, any 25 kHz discrete UHF air-ground communications channel in the band 225-400 MHz).

b. Power output of an ATIS operating on a discrete VHF or UHF channel should not exceed 10 W.

c. Service volume of an ATIS operating on a discrete VHF or UHF channel must be consistent with the Terminal Radar Approach Control (TRACON) airspace, and is normally limited to 60 nmi and 25,000 feet above ground level (AGL). The concerned service area air traffic organization must approve requirements in excess of this value.

d. Frequency protection ratio (D/U) for an ATIS operating on a discrete VHF or UHF channel shall be a minimum of: (1) 14 dB from an aircraft at the edge of the ATIS service volume to another cochannel ATIS, Automated Weather Observing System (AWOS) or Automated Surface Observation System (ASOS).

(2) Beyond RLOS separation from a potential interferer at the edge of an FPSV to the transmitter site of the ATIS.

NOTE : The minimum separation is inclusive, i.e., both (1) and (2) must be met.

e. If the proposed ATIS facility does not conform to subparagraphs (1) through (4) above, the FAA may not assign the system a broadcast frequency.

905. AWOS/ASOS FREQUENCY ASSIGNMENT CRITERIA . (These criteria also apply to other weather broadcast services under different names.) The following criteria shall be used to the maximum extent possible in selecting AWOS/ASOS voice outlets: a. Priority for selecting a frequency to support AWOS/ASOS broadcasts: (1) At airports with towers , use the existing ATIS voice outlet, if available. If the tower operates part-time, the AWOS/ASOS shall operate independently of the ATIS during non-operational hours.

(2) At airports without ATIS , use a non-Doppler VOR or VORTAC site if it is within 3 nmi of the AWOS/ASOS facility. This only applies to those VORs that do not currently use the facility for other broadcast signals such as EFAS.

(3) If no ATIS or VOR is available , the AWOS/ASOS facility shall be assigned an available 25 kHz air/ground frequency, with first consideration given to (a) or (b) below.

(a) 120.000 MHz is available for AWOS/ASOS requirements at non-air traffic control tower locations, and at air traffic control tower locations if the AWOS/ASOS transmit antenna is located at least 2,000 feet from the tower cab.

(b) The frequencies 121.425, 121.450, 121.550, and 121.575 MHz (i.e., guard band frequencies for 121.500 MHz) are available for FAA AWOS/ASOS installations, subject to stringent emission mask requirements. These frequencies shall not be used to satisfy non-FAA requirements unless coordination is undertaken with Technical Operations ATC Spectrum Engineering Services to ensure that special action is taken to implement sufficiently stringent emission masks, as part of the transmitter specifications, and on-going maintenance procedures to satisfy the special requirements of using these frequencies.

Page 83 6050.32B Chapter 9 - continued 11/17/05 b. If a Nondirectional Beacon (NDB) is available and desired , the AWOS/ASOS may be broadcast over the NDB, when the AWOS/ASOS facility will be within 3 nmi of the NDB. This does not apply to two- frequency NDBs that are not capable of voice transmission. The NDB frequency must be in the 325-415 kHz range to support voice.

c. Power output of an AWOS/ASOS operating on a discrete VHF channel should not exceed 2.5 W.

d. Service volume of an AWOS/ASOS operating on a discrete VHF shall not be less than 15 nmi and 5,000 feet AGL and is normally limited to 25 nmi and 10,000 feet AGL. Requirements in excess of this value must be approved by the concerned service area air traffic organization. Under no circumstances shall the radius of the service volume exceed the terminal control area.

e. Frequency protection ratio (D/U) for an AWOS/ASOS operating on a discrete VHF channel shall be a minimum of: (1) 14 dB from an aircraft at the edge of the AWOS/ASOS service volume to another co-channel ATIS, AWOS or ASOS.

(2) Beyond RLOS separation from a potential interferer at the edge of an FPSV to the transmitter site of the AWOS/ASOS. NOTE : The minimum separation is inclusive, i.e., both (1) and (2) must be met.

f. If the proposed AWOS/ASOS facility does not conform to the criteria in subparagraphs a. through e.

above, the FAA may not assign the system a broadcast frequency.

906. BACKUP COMMUNICATIONS. In many cases, backup communications facilities are maintained to preclude a total loss of services at air traffic control facilities. In the enroute environment the Backup Emergency Communications system (BUEC) has been in place for many years. In the large TRACON environment there are now many facilities with Emergency Communications Systems (ECS) that function much like the enroute BUEC systems. Many airports also separate their primary and secondary radios to eliminate single points of failure in their communications system. Additionally, most towers have portable battery operated radios for emergencies.

a. The enroute BUEC radio system is changing from a system that used a few strategically located tunable radios to provide backup service for the enroute facilities to a system that has a dedicated fixed tuned radio for each enroute sector. This new Sustaining BUEC system is being implemented within the Sustaining BUEC program.

(1) The tunable BUEC system has been scheduled for de-commissioning and removal by early 2006. It was typically located at enroute radar sites because of the access to the FAA microwave backbone as an alternative means of connecting to the ARTCCs. These tunable BUEC radios were not easily colocated with most fixed tuned FAA radios, because they were more susceptible to cosite RFI than the fixed tuned FAA radios.

(2) The Sustaining BUEC system provides a dedicated backup radio tuned to the ATC sector frequency for each primary transmitter supporting a sector. The FMOs shall ensure that the site selected for the location of the Sustaining BUEC radio provides the necessary coverage for the sector or portions of the sector that the primary facility covers, and must satisfy the full frequency engineering criteria for a Remote Control Air/Ground (RCAG) frequency assignment. A Sustaining BUEC shall not be colocated in the same facility as the primary radio. Any exceptions to these requirements must be justified by waivers jointly approved by Technical Operations, and Enroute and Oceanic Services.

Page 84

6050.32B CHG - 3 06 / 11 /19 CHAPTER 10. NAVIGATIONAL AID (NAVAID) FREQUENCY ENGINEERING 1000. PURPOSE . The purpose of this chapter is to present an overview of the frequency engineering necessary for ILS [including Transponder Landing System (TLS)], VOR, VHF Omnidirectional Radio Range Test (VOT), Area VOT (AVOT), Distance Measuring Equipment, Normal (DME/N), Precision Distance Measuring Equipment, Precision (DME/P), Tactical Air Navigation (TACAN), Microw ave Landing System (MLS), Local Area Augmentation System (LAAS), Wide Area Augmentation System (WAAS), Automatic Dependant Surveillance - Broadcast (ADS - B) and the Global Positioning System (GPS). The detailed frequency engineering for these NAVAID facilit ies is discussed in Appendix 3.

1001. NAVAID FREQUENCY ALLOCATION . The concept of navigational performance involves the precision that must be maintained for both the assigned route and altitude by an aircraft within a particular area. ATC can only appl y separation minima within areas where the NAVAID signal meets flight inspection signal strength and course quality standards, including frequency protection, within its designated operational service volume.

Therefore, these allocations are preferential bands reserved for frequency assignments to those aeronautical radio - navigation services that fundamentally support, assist or enable the functions to navigate and to separate an aircraft from other aircraft or hazards. Additionally, the frequency protect ion criteria (i.e., facility separation distances) dictate the number of protected, co - and adjacent channel facility assignments that can exist within the confines of their geographical borders. That makes the frequency availability a finite resource whe n engineering a facility’s assignment, especially for regions surrounding the busiest airports. The management of frequency availability depends on the NAVAID frequency allocations are reserved for their intended services to aircraft navigation. The use o f these frequencies by systems for otherwise stated poses a flight safety risk for air traffic if it degrades navigational performance which, in turn, translates into a loss of separation minima. Plus, the stewardship of these frequencies is vital for eng ineering the future NAVAID frequency assignments needed to support increased signal coverages for NextGen Initiatives such as Performance - Based Navigation. NAVAID facilities are dependent upon the use of the RF spectrum. A summary of the present internatio nal and national frequency allocations for NAVAID is shown in figure 10 - 1.

FIGURE 10 - 1. NAVAID BAND USE FACILITY TYPE FREQUENCY BAND (MHZ) ILS LOCALIZER (LOC) 108.1 - 111.95 LAAS 112.0 - 117.975 ILS GLIDESLOPE (GS) 328.6 - 335.40 ILS MARKER BEACON 75 ADS - B 978.0 VOR, VOT, AVOT 108.00 - 117.975 DME/N, DME/P, TACAN 960.0 - 1215.0 MLS 5031.0 - 5090.7 GPS L5 1176.45 GPS L1 1575.42 1002. BASIC PRINCIPLES OF NAVAID FREQUENCY ENGINEERING . Due to the fixed number of frequencies available for NAVAID facilities, each NAVAID frequency is reused as often as possible throughout the country. NAVAID frequency engineering provides an interference - free assigned environment for each NAVAID facility within its FPSV. Each type o f NAVAID has its own characteristic FPSV, and each is defined in Appendix Page 91 6050.32B CHG - 3 06 / 11 /19 3. NAVAID frequency engineering involves two frequency analyses: intersite and cosite.

a. Intersite Analysis is necessary to prevent RFI between facilities on the same and adjacent freque ncies providing service in different or adjacent areas. The basic factor considered in intersite analysis is the D/U ratio, as seen at the airborne NAVAID receiver input. All NAVAID frequency assignments must meet certain D/U ratio values (see Appendix 3). For example, a VOR assignment must meet 23 dB ratio for cochannel D/U within its FPSV. The 23 dB ratio is based upon the ICAO standard of required 20 dB D/U ratio, with the addition of a 3 dB factor to allow for the facility power decreasing 3 dB before i ts monitor shuts it down. The required D/U ratios for each type of VHF/UHF/SHF NAVAID for cochannel and adjacent channels are provided in Appendix 3. 6050.32B b. Cosite Analysis is necessary to prevent RFI resulting from the interaction of transmitters and receivers at or near the same site. Cosite RFI includes intermodulation products, cross - modulation, receiver desensitization (overload), adjacent channel signals, harmonics and AM/FM/TV interference.

1003. NAVAID FREQUENCY ENGINEERING METHODS . The cosite analysis procedure is discussed in Appendix 3. It will not be repeated in this chapter. As for intersite analysis, there are two basic methods for determining whether a proposed frequency meets the required D/U ratio criteria.

a. Method 1: Use of Reference Tables . A series of reference tables will be found in Appendix 3, which shows conservative worst - case separation distances required for each NAVAID type. If the proposed new facility meets all the separation requirements of appropriate reference tables, no further search is necessary, and the frequency application may be prepared. This method is discussed in detail in Appendix 3.

b. Method 2: Calculation of Required Separation . In frequency - congested areas, it is necessary to use a more accurate and detailed method of determining the required separation distance. The calculation method takes the following equipment parameters into consideration and the required D/U ratio is adjusted accordingly: (1) Transmitter power .

(2) Antenna gain .

(3) Antenna directivity .

(4) Antenna orientation .

1004. EQUIVALENT SIGNAL RATIO (ESR) . The adjusted D/U ratio is called ESR. A series of curves based on this ESR will be found in Appendix 3, showing the required separation distance. The detailed procedure for calculating the ESR and using the curves is discussed in Appendix 3.

1005. EXPANDED SERVICE VOLUME (ESV) . An ESV is a special volume of airspace outside of the normally specified FPSV. Each ESV is engineered using the same criteria as for the FPSV. In addition to meeting the re quired D/U ratio criteria, each ESV shall also meet certain minimum signal strength requirements as prescribed in Appendix 3. Since ESVs are not registered in the NTIA GMF, Technical Operations ATC Spectrum Engineering Services maintains a separate data ba se within the AFM for all ESVs used in the NAS. The detailed procedures for engineering ESVs and updating the ESV data base are discussed in Appendix 3.

1006. SPECIAL ISSUES TO BE CONSIDERED .

a. NAVAID 50 kHz Assignments . Since some general aviation aircr aft may not yet be equipped with 50 kHz (200 - channel) navigation receivers, every effort shall be made to find a 100 kHz assignment for a NAVAID facility before assigning a 50 kHz channel.

Page 92 6050.32B CHG - 3 06 / 11 /19 b. Paired NAVAID Assignments . To minimize a potential safety hazard, frequency protection shall be provided for all services associated with a facility, even if only one service is installed. When an ILS LOC is assigned, the associated DME frequency shall be frequency protected even if no DME is installed. The same holds tr ue for VOR/DME/TACAN and MLS/DME/P and MLS/DME/N.

c. Localizer Receiver Desensitization Due to In - Band Localizer Signals . Interference between localizers serving different runways at the same airport is possible depending on the configuration of the runways and the distance between the two systems. When an aircraft on approach passes through a strong radiation field of a localizer serving a reverse or an adjacent runway, the ILS siting criteria (FAA Order 6750.16) requires that a positive interlock device b e installed to prevent both systems from transmitting simultaneously. FMOs may be asked to evaluate waivers to this siting policy at airports where more efficient use of runways is required.

The FMO must analyze the specific situation and geometry so that airborne ILS avionics are not desensitized due to other localizers at the airport. The following policy is provided: (1) An undesired localizer signal level of - 33 dBm will not be exceeded within the FPSV of a collocated ILS.

(2) Calculations will be done using the free space formula.

d. VOR/DME/TACAN Collocation Assignments . Some VOR/DME/TACAN facilities that were in place in 1980 were engineered under criteria slightly different than that shown in Appendix 3. As such, any installations, which have passed flight inspection satisfactorily in the past, shall be considered as conforming to these criteria.

However, any new facility frequency engineered shall adhere to the criteria presented in Appendix 3.

(1) The greater distance separation of the individual frequency paired VOR/DME/TACAN shall be used.

In facilities of equal power, the criteria charts and graphs will show that the DME/TACAN required separation is greater than that of any paired VOR for most conditions.

(2) In all cases , the GREATER requirement shall be us ed as minimum separation for the frequency pair, regardless of whether both paired facilities are installed.

e. DME at ILS Locations . ILS/DMEs generally require separation distances far beyond that provided for the LOCs due to the DME's separation criteria a nd omnidirectional antenna pattern. Therefore, it is important to ensure that when engineering an ILS LOC frequency, its associated DME meets the required separation, even if no DME is installed. In frequency congested areas, the frequency protection for t he DME may not be possible without using 50 kHz NAVAID frequencies. If the DME is not actually installed, the DME frequency protection may be waived through the normal NAS Change Proposal (NCP) process.

f. DME/P and DME/N at MLS Locations . The conditions are the same as with DME at ILS locations.

g. Potential FM/TV Interference . Because of an abundance of FM and TV high power transmitters around the country, an approach or an airway may place an aircraft over or very near one of these transmitters. Their ove rwhelming power, frequently on the order of a megawatt or more ERP, can cause severe overloading of the front end of aircraft receivers, and thus the loss or deterioration of NAVAID reception. A routine item to be checked for problems in a frequency study shall include the verification of nearby FM or TV transmitters. Of particular concern are the FM transmitters near the upper end of the FM broadcast band because it is immediately adjacent to the 108.0 - 117.975 MHz NAVAID band. All new ILS and VOR proposals will be evaluated using the AAM to determine the potential for any interference from FM and TV Broadcast stations. See Appendix 1 for further discussion of FM/TV interference.

h. Collocated NAVAIDS . At some sites, a VOR/DME/TACAN or ILS/DME paired facilitie s may not be Page 93 6050.32B CHG - 3 06 / 11 /19 actually collocated. To meet ICAO and FAA standards, such paired facilities must be installed within the distances specified in the Appendix 3, or else the two facilities may not be frequency paired. An ILS/DME may be collocated with either t he LOC or the GS transmitter .

i. Terrain Shielding . A transmitter's signal strength in space can be affected by the shielding of terrain, buildings, vegetation, etc. This can have an impact on the D/U signal ratios in space. If shielding is severe, it may be possible to provide the required D/U signal ratios with less than the recommended station separation.

The use of terrain shielding, as a way to decrease the separation requirement, should be treated on a case - by - case basis through sound engineering judgmen t. This facility must be flight checked with satisfactory results and documented through the normal NCP process.

j. LAAS spectrum support will be referred to Technical Operations ATC Spectrum Engineering Services for engineering and assignment action.

k. ADS - B currently uses the Universal Access Transceiver (UAT) and transmits on 978.0 MHz. The UAT transmits ADS - B data air - to - air for cockpit display and air - to - ground for use by ATC. The UAT may receive ground - to - air Flight Information Service (FIS) and Traffic Information Service (TIS) data for cockpit display.

l. WAAS transmits on GPS frequency L1 from geosynchronous satellites that cover the continental U.S.

(excluding Alaska).

m. GPS frequency L5 is expected to be implemented starting with the Wide Area Augmentation System (WAAS) geostationary satellites by 2007, with the GPS constellation implementation to follow in the 2010 - 2015 time frame. Since L5 transmits on 1176.45 MHz, it was previously considered that some TACAN/DME frequency changes might need t o be made to accommodate L5. However, after considerable study it has been concluded that no TACAN/DME frequency changes will be required in the NAS to provide satisfactory L5 operation.

n. VOR Service Volumes and DME Service Volumes. Frequency requests for VOR MON and NextGen DME Service Volumes are based on the most current version of the following program requirements: 1. Very High Frequency Omnidirectional Radio Range Minimum Operational Network (VOR MON) Program Final Program Requirements Document ( fPRD) 2. NextGen Distance Measuring Equipment (DME) Program Final Requirements Document (fPRD) If any concerns with coverage or service availability are encountered when engineering NAVAID frequencies to support the VOR MON or NextGEN DME program requiremen ts, those concerns should be coordinated through AJW - 1C2 to the PMO.

1007. thru 1099. RESERVED Page 94 6050.32B CHG - 3 06 / 11 /19 Page 9 5 (thru 98)

11/17/05 6050.32B CHAPTER 11. LOW/MEDIUM FREQUENCY (L/MF) GROUND NAVIGATIONAL AIDS 1100. PURPOSE . The purpose of this chapter is to describe the necessary techniques and actions required to provide a frequency for a low/medium frequency (L/MF) NAVAID. L/MF includes Compass Locator (COMLO) and Nondirectional Beacon (NDB), also known as a "Homer."

a. The COMLO is an NDB , usually of low power, strategically located on an ILS approach path to provide L/MF azimuth guidance to an airport, in addition to the more precise guidance of the ILS LOC. COMLOs are normally collocated with ILS Outer Markers (OM) and Middle Markers (MM), and referred to as "LOM" and "LMM," respectively. The LOM transmits, in Morse code, the first two letters of the associated ILS identifier.

The LMM transmits the last two letters of the associated ILS identifier. For example, COMLOs installed with the Los Angeles, CA (LAX) ILS would be "LA" for the LOM and "AX" for the LMM. To the extent possible, the frequencies of the LOM and LMM shall not be separated less than 15 kHz nor more than 25 kHz.

b. The NDB is a free-standing nondirectional radio beacon designed to provide navigational service over a specified radial distance from the facility. It can have power from 10 W to 1000 W, typically 25 W, depending on the need. It should be noted that due to very heavy congestion in this band, the FMO shall do everything possible, by coordinating with the concerned service area air traffic organization and FS, to engineer the lowest possible emitted power to cover the requirement. The Aeronautical Information Management (AIM) in System Operations Airspace and AIM is responsible for the coordination of requests for three-letter location identifiers.

Coordination with this organization is accomplished by each service area through the concerned air traffic organization.

1101. GENERAL CONSIDERATIONS .

a. NDB and COMLO are treated the same for frequency assignment purposes. For simplicity, only the term NDB will be used hereafter when it is intended to refer to both.

b. An NDB frequency selection model is available on the AFM for engineering NDB requirements.

c. A required signal level of 70 microvolts per meter (uv/m), which is also 37 dB above one microvolt per meter (dBuv/m), is the standard set for the signal required at all points on the outer limits of the NDB FPSV. If the NDB transmitter power decreases by 3 dB, the resultant signal would be equivalent to 50 uv/m at all points on the outer limits of the NDB FPSV. At this point, the remote NDB alarm is triggered.

d. The D/U signal level standard for an NDB is 15 dB. This provides an assured 12 dB protection of the FPSV when the desired signal decreases 3 dB from the normal operating power. At this point, the system should alarm.

e. Channelization of the band is 1 kHz . First adjacent channel is 1 kHz removed, second adjacent is 2 kHz removed, etc.

f. The mode of radiation is considered to be ground wave, while acknowledging that, particularly at night, sky wave does enter into propagation mode.

g. The FPSV is considered to be a cylindrical volume of airspace, centered on the NDB, with no upper altitude limit. Since the ground wave is the principal radiation factor, the signal level in any given direction is a function of the antenna efficiency, the ground system associated with the antenna and the ground conductivity medium through which the signal passes to get to the point under consideration.

Page 99 6050.32B Chapter 11 – continued 11/17/05 h. NDB FPSV's are classified as follows: (1) LOM/LMM 15 nmi radius (2) MH (less than 50 W) 25 nmi radius (3) H (50 w or more, but less than 2,000 W) 50 nmi radius (4) HH (2,000 W or more) 75 nmi radius i. An NDB's primary function is as a NAVAID , However, voice modulation is permitted in addition to the required Morse code identifier only on a secondary basis, and then only when it causes no interference to any other facility as a result of the additional voice modulation.

j. An NDB for non-Federal use , which requires a frequency request through FCC, has the same priority as an FAA or other Federal agency facility, provided that the proposed NDB has an FAA approved procedure on it.

Any other non-Federal use is on a secondary basis, assignable only if: (1) The facility could be accommodated without moving or otherwise affecting FAA facilities in any way.

(2) FAA concurrence with use of the frequency is contingent upon the frequency being withdrawn upon notice by FAA in writing at any time it is needed for a facility which has a procedure and is in the NAS.

k. Permissible power is that normal power level which just meets the level required to assure 70 uv/m at the circumference of the FPSV. In some unique instances, due principally to poor ground conductivity, it may be impossible to meet the signal level requirement at some azimuths. In this case, an option, if FS and the concerned air traffic organization concur, could be to commission with restrictions.

l. There is little difference in the signal level between ground and any altitude normally flown by aircraft within the FPSV specified. As a general rule, the signal level measured at any altitude is considered to be the same as found at ground level and all other altitudes at that azimuth.

m. A dual carrier NDB has an upper sideband (only) with full carrier. It radiates a Continuous Wave (CW) carrier on the assigned frequency. The identification signal is provided by an on/off keying of a second carrier, transmitted at a frequency equal to the first carrier frequency plus the frequency of the modulation tone. For example, at a carrier frequency of 200 kHz, the second carrier would be at 200.4 kHz (for a 400 Hz identifier) and at 201.02 kHz (for a 1020 Hz identifier). For purposes of registering in the GMF, the emission designator would be 500HXXA and the center frequency would be 200.2 kHz (for a 400 Hz identifier) and 1.112XXA emission designator and 200.51 kHz center frequency (for a 1020 Hz identifier).

1102. FREQUENCY ALLOCATION FOR L/MF FACILITIES . The frequencies allocated for L/MF use are shown in figure 11-1.

Page 100 11/17/05 Chapter 11 - continued 6050.32B FIGURE 11-1. L/MF NAVAID FREQUENCY ALLOCATIONS Frequency Limitations & Comments (kHz) 190 - 200 AR Primary 200 - 275 AR Primary; AM Secondary 275 - 285 AR Primary; AM Secondary; MR Secondary 285 - 325 MR Primary; AR Secondary 325 - 335 AR Primary; AM Secondary; MR Secondary 335 - 405 AR Primary; AM Secondary 405 - 415 R Primary; AM Secondary 415 - 435 MM Primary; AR Primary 510 - 525 AR Primary; MM Primary 525 - 535 AR Primary; M Primary KEY AR - Aeronautical Radionavigation (FAA & Non-Fed. NDB's) MR - Maritime Radionavigation R - Radionavigation MM - Maritime Mobile M - Mobile (For detailed definitions, see NTIA Manual, Chapter 6.)

a. NDB voice is not permitted in the bands 190-199.9, 285-324.9, and 415-535 kHz.

b. The band 525-535 kHz use by Mobile Service is limited to the Travelers' Information Service (TIS), operating on 530 kHz. Voice modulation of NDB's is not permitted in this band.

AR stations are authorized for off-shore use only, on a non-interference basis to TIS.

c. Maritime radiobeacons in the 285-325 kHz band segment will not be used for aeronautical operations. In addition, FMO's will avoid use of the 285-325 kHz band segment for aeronautical radiobeacons because of the incompatibility between aeronautical NDB receivers and the maritime NDB's which transmit DGPS signals for use by maritime users.

Page 101 6050.32B Chapter 11 – continued 11/17/05 1103. ENGINEERING CONSIDERATIONS FOR L/MF FREQUENCY SELECTION . It is unfortunate, but frequency engineering for L/MF facilities is not a straight-forward technical operation. There are several reasons for this.

a. L/MF propagation is not an omnidirectional straight line decay of signal situation. Since ground wave is involved to a considerable degree with the conductivity of the ground in each azimuth direction, there can be wide variations of signal strength in different directions from a single antenna.

(1) An antenna near a body of water , particularly ocean water, will have greatly increased radiation in the azimuths covered by the ocean, while inland azimuths will retard radiation due to signal losses caused by poorer conducting earth. As an example, an NDB on the northern Florida east coast will have very efficient radiation into the Atlantic Ocean. But because the ground conductivity is very poor there, signals radiated to the west would be much reduced.

(2) A specific example would be that at 50 nmi to the west, a signal of 20 uv/m would be measured from a 25 W NDB. The same signal measured eastward to sea (assuming the NDB to be on or very close to the beach) would produce 70 uv/m, or an approximately 11 dB stronger signal.

(3) Night-effect can occur because an NDB radiates both a ground wave and a sky wave. The ground wave is usable for navigation within the operational service volume. The sky wave is radiated up into space and reflected back to earth by the ionosphere. This reflection results in the presence of an attenuated sky wave at varying distances from the NDB ground station. The distance and the amount of attenuation are determined by the height and density of the ionosphere and the angles at which the radiated sky wave strikes the ionosphere.

Sky wave field strength is subject to changes in the ionosphere. This is similar to the conditions for HF described in chapter 7. These changes occur as a function of the time of day, time of year and phase of the solar cycle. At night, the reflective property of the ionosphere increases for L/MF and the lower HF bands resulting in a sky wave field strength that can be substantially larger than during the day.

b. A ground system consisting of four copper wires, equally spaced radially about the base of the antenna, would give a smaller signal at any given point as compared to the same antenna with 30 equally-spaced copper radials.

c. There are no "standard" antennas , so whatever antenna is installed will affect the radiation efficiency.

The most common antennas used are the symmetrical "T" and the top loaded vertical or "Top Hat."

d. Ground conductivity charts are only approximate, and the various curves used are an average of empirical data.

e. With all those limitations , it can be seen that the process which will be described is only an estimate of the level of signal to be expected at the periphery of the FPSV.

Page 102 11/17/05 Chapter 11 - continued 6050.32B FIGURE 11-2. ESTIMATED GROUND CONDUCTIVITY IN THE UNITED STATES Page 103 6050.32B Chapter 11 – continued 11/17/05 1104. BASIC TOOLS . The basic tools used in engineering frequencies for L/MF are the ground conductivity map and the prediction curves.

a. The Ground Conductivity Map . Refer to figure 11-2. The conterminous U.S. (CONUS) is divided up into small "jig-saw" segments with numbers in each piece. Those numbers are the numerical value of "millimho/m" (mm/m) and represent units of reluctance, the unit used to represent average electrical conductive quality of the ground in the area. A value of 1 to 4 is poor; 8 is good; 15 and 30 are so good that they are practically indistinguishable from sea water. Sea water, the reference at 4,000, is the ideal. These values will be more meaningful when they are compared with the other tool, the coverage and interference prediction curves.

b. Prediction Curves . Refer to figure 11-3. These curves are designed to give the user a predicted level of signal at a given distance from the transmitter. The three shaded curves are for "poor" ground at 1 to 4 mm/m, "good" ground at 8 mm/m and sea water at 4000 mm/m. Conductivity values between 1 and 4000 must be interpolated.

(1) There is a frequency factor in the curves. The frequency range covered is over 2:1. Conductivity varies with frequency so that the left side of each curve is 400 kHz and the right side is 200 kHz. Frequencies in between must be interpolated.

(2) The curves are normalized to 300 kHz and so have an antenna efficiency factor which is shown between 200 kHz and 400 kHz. The antenna radiation correction factor for frequencies in between must be interpolated.

(3) There are corrections for receiver intermediate frequency (IF) selectivity. While newer receivers will have quite sharp IF selectivity, until such time as the large majority of airborne receivers are of that group, the receiver correction values shown on the chart shall be used.

(4) Typical facility types , as related to average radiation level from usual antennas, are shown as a series of parallel straight lines. Where the line intersects the 0 dB abscissa, the indicated μ v/m value (good only on the "0 dB" line) is that predicted at 1 nmi.

(5) The vertical scale for the abscissas is the dB value below signal voltage level at 1 nmi. For instance, the 25 W NDB line shows an expected level of 3700 uv/m at 1 nmi. Its intersection with the 70 uv/m service radius at the -34.5 dB abscissa, when followed to the inverse distance line, indicates that a level of 70 uv/m would occur over perfectly-conducting ground at 50 nmi. In propagation, field voltage decays inversely as the distance.

Power varies inversely as the square of the distance. A signal voltage at 2 nmi is 6 dB less than that signal level at 1 nmi. The "inverse distance" line runs from 1 mv/m to 1000 mv/m. The distance and voltage are inversely proportional and their ratio is 1000:1. It can be seen that dB = 20 log (E1/E2) = 20 log 1000 = 20 X 3 = 60 dB.

The inverse distance line is from 0 to –60 dB.

Page 104 11/17/05 Chapter 11 - continued 6050.32B FIGURE 11-3. COVERAGE AND INTERFERENCE PREDICTION CURVES Page 105 6050.32B Chapter 11 – continued 11/17/05 1105. ENGINEERING PROCEDURES .

a. Conductivity . Required facility geographical separation (S) is calculated by using figures 11-2 and 11-3.

Figure 11-2 shows the ground conductivity in mm/m which determines which curves to use in figure 11-3.

b. Separation Distance (S) . (S) is the minimum distance required between facilities to prevent interference and is defined as:

(S )= d + d

D U where d = distance from the desired facility to the edge of its service volume D d = distance from the undesired facility to the edge of the desired service volume U c. Calculation of Required Separation Distance .

(1) Find the facility service volume d in nmi on the bottom of figure 11-3. Move up to intersect the D appropriate ground conductivity curve from figure 11-2, interpolating for frequency. Note the attenuation value in dB at the left of figure 11-3.

(2) Add the antenna radiation correction factor shown in figure 11-3 to the dB value in subparagraph 1.

(3) Algebraically add the correction factor to subparagraph 2 for difference in facility power. For example, if the undesired facility is 50 W and the desired facility is 25 W, add -3 dB.

(4) Add the receiver correction value to subparagraph 3 when the undesired station is within ±6 kHz of the desired station. The "Undesired receiver correction with voice" shall be used first. If a frequency cannot be engineered using that value, the "Undesired receiver correction without voice" may be used only if the desired station does not have transmit voice.

(5) Algebraically add -15 dB to the value obtained in subpara. 4; this gives the D/U ratio of 15 dB required.

(6) Use the dB attenuation value obtained in subparagraph 5 and find this level at the left of figure 11-3.

Move across to intersect the appropriate conductivity curves. This intersection determines d in nmi from the U bottom scale.

(7) Add d and d to obtain the required separation (S) distance necessary for the desired facility to have D U a minimum of 15 D/U.

(8) Determine the required (S) for the undesired facility in the same manner (now the undesired is the desired and vice versa).

Page 106 11/17/05 Chapter 11 - continued 6050.32B 1106. PRACTICAL EXAMPLE . See figure 11-4.

FIGURE 11-4. GEOGRAPHIC SEPARATION EXAMPLE a. Station A , the desired station, is on 400 kHz, power 25 W, FPSV 25 nmi, with conductivity of 2 mm/m.

b. Station B , the undesired station, is on 400 kHz, power 50 W, FPSV 25 nmi, also 2 mm/m.

c. Calculating Station A Distances .

(1) Find the facility d of 25 nmi FPSV at the bottom of figure 11-3. Move up and intersect the 400 kHz D 2 mm/m curve. Note the attenuation value of -37.5 dB at the side of the graph.

(2) Algebraically add -3 dB radiation correction factor to the value of subparagraph 1: -37.5 + (- 3) = -40.5 dB.

(3) Determine the dB power difference : P /P = 25/50. 10 log ½ = -3 dB. Add that value to the value D U of subparagraph 2: -40.5 - 3 = -43.5 dB.

(4) Determine the receiver correction value . In this example, the stations are on the same frequency, receiver correction is 0 dB, so the value remains -43.5 dB.

(5) Algebraically add -15 dB to the value obtained in subparagraph 4: -43.5 + (- 15) = -58.5 dB.

(6) Find the value -58.5 dB at the left of figure 11-3 and move across to intersect the 400 kHz curve for 2 mm/m. From the scale at the bottom of the graph, note the value is 90 nmi.

(7) Add d + d = 25 + 90 = 115 nmi, the required separation for (S).

D U Page 107 6050.32B Chapter 11 – continued 11/17/05 d. Calculating Station B Distances .

(1) Find the facility FPSV d of 25 NM at the bottom of figure 11-3. Move up and intersect the 400 kHz D 2mm/m curve. Note the attenuation value of -37.5 dB. See subparagraph c(1).

(2) Algebraically add -3 dB antenna radiation correction factor to value of subparagraph 1: -37.5 + (- 3) = -40.5 dB.

(3) Determine the dB power difference : P / P = 50/25. 10 log 2 = +3 dB. Add that +3 db to the value D U of subparagraph. 2: -40.5 + 3 = -37.5 dB.

(4) Determine the receiver correction factor to be 0 dB, so the value remains at -37.5 dB.

(5) Algebraically add -15 dB to the value in subparagraph 4: -37.5 + (-15) = -52.5 dB.

(6) Find the value -52.5 dB on the side of figure 11-3 and move across to intersect the 400 kHz 2 mm/m curve. Note the value is 65 nmi.

(7) Add d + d = 25 + 65 = 90 nmi, the required (S).

D U (8) Compare the required separations for each calculation. Note that the larger requirement is 115 nmi, and the larger is always used.

1107. AIRBORNE MEASUREMENTS .

a. The same kind of measurements (for the proposed facility) could be made from a flight inspection aircraft. The problem is in the receiving antenna in the aircraft. A calibrated loop remains as a calibrated entity only as long as its surroundings are nominal, or at least not changing. With a loop on an aircraft, any change of aircraft position with respect to the plane of the loop which has to be maximized with respect to the signal source will nullify its calibration. The cost of using a flight inspection aircraft is prohibitive to be used as a "study" vehicle.

b. A FAA Study covering a comparison of airborne and ground measurement was completed in 1980. A thorough report of that study is available for FMO consideration in Report No. FAA-R-6050.2, Low Frequency Beacon Signal Strength Determination, dated January 1980.

1108.-1199. RESERVED .

Page 108 (thru 110)

11/17/05 6050.32B CHAPTER 12. MICROWAVE DATA/COMMUNICATIONS LINKS FREQUENCY ENGINEERING 1200. PURPOSE . This chapter and its associated appendix provide the criteria for the engineering of frequencies for each of the type of links indicated in the title. It does not supersede or replace existing maintenance or installation instructions, but rather provides only that technical data required to provide the frequency engineering necessary for each facility. Coordination between the frequency engineer and the installation staff is essential to assure system viability.

1201. FREQUENCY BANDS AVAILABLE FOR RADIO LINKS . Radio frequency link engineering involves two frequency analyses, cosite and intersite. The following bands are available for links as indicated.

FIGURE 12-1. BANDS CURRENTLY USED BY FAA FOR RADIO LINKS 162-174 MHz Land Mobile* Very congested band 406.1-420 MHz Land Mobile* Very congested band 932-935 MHz Fixed Station LDRCL 941-944 MHz Fixed Station LDRCL 1710-1850 MHz Fixed Station** LDRCL 7125-8500 MHz Fixed Station Radio Communications Link (RCL) 14.4-15.35 GHz Fixed Station TV Microwave Link (TML) 21.2-23.6 GHz Fixed Station Microwave links * Specific frequencies are allotted for fixed operations such as Low Level Windshear systems (LLWAS), RMM, MALSR, etc. (See chapter 17.)

** New requirements for radio links will not be satisfied in the 1710-1850 band.

a. The band 7125-8500 MHz is broken up by segments allocated to space communications. Only the subbands 7125-7250, 7300-7900, and 8025-8500 MHz are available for fixed PTP links.

NOTE: The FR8 RCL will not operate in the 8400 to 8500 MHz band.

b. The band 14.5-15.35 GHz is broken into three sections. The portion 14.7145-15.1365 GHz is allocated to other services on a primary basis. This subband must be avoided in planning Television Microwave Link (TML) systems.

Page 111 6050.32B Chapter 12 – continued 11/17/05 c. Because of the wide variety of microwave equipment used by FAA, detailed engineering criteria are not provided for all such systems. Detailed engineering criteria are provided for the FR8 because of its extensive use.

In general, when doing spectrum engineering for microwave systems, the intersite engineering should be done first, since it is straightforward. When analyzing the cosite situation, care must be taken that image frequencies of the system are considered. The appropriate manufacturer's equipment specifications should be consulted and the general procedures of paragraph 1204 followed.

1202. INTERNATIONAL COORDINATION REQUIREMENTS . When systems are to be designed for use within 100 nmi of the Canadian or Mexican borders, Technical Operations ATC Spectrum Engineering Services should be notified very early in the project. There are international agreements with Canada and Mexico that require coordination. Early coordination can prevent having to vacate a planned frequency group when it is found to conflict with their operations.

1203. TECHNICAL STANDARDS FOR LINKS . See Chapter 5 of the NTIA manual. Technical data for FAS applications for U/SHF systems are found in appendix 4.

1204. THE GENERAL PROCEDURE FOR MICROWAVE LINK INTERSITE FREQUENCY ENGINEERING is basically an orderly step-by-step compilation of all the parameters of all potentially competing systems. It simply consists of carefully examining every parameter that would affect the overall RF path from a transmitter output to a receiver input. Essentially, the frequency is unimportant to the procedure because the procedure is the same for 900 MHz as it is for 21 GHz. While Technical Operations ATC Facilities sets the physical path, the frequency engineer must check the spectrum compatibility both as a potential interferer to other established systems (culprit) and as a potential receiver of RFI from other systems (victim). See figure 12-3. The following is a general discussion of the detailed procedure followed by a simple format that is intended to assist in assuring that all parameters are considered as well as providing a study record of each system analysis.

a. While the actual site path will be engineered by Technical Operations ATC Facilities , the frequency engineer must be sufficiently familiar with certain of the engineering parameters to assure that the frequencies engineered will work with the system.

b. Cosite considerations. Of particular importance are other microwave systems. For instance, the second harmonic of much of the 7125-8500 MHz band falls into the 14.50-15.35 GHz band. FAA is not always able to site its equipment on an exclusive FAA site, thus any other users' equipment must be considered.

c. Intersite and near parallel path considerations. The site shall be frequency engineered by checking the GMF carefully for the full bandwidth of FAA's equipment and add to that the bandwidth of any other user's equipment operating in the area. The parameters for determining the signal level at a victim receiver include the proximity of frequency, receiver band pass characteristics, and the geographical location of the victim receiver.

Determination of the required azimuth separation from other users is also a matter of parameters as described in paragraph d.

d. From the transmitter end , there are several parameters to be considered.

(1) Transmitter output power , specified in dBm, normally a positive value.

(2) Wave guide (feed line) power loss , in dB, always a negative value.

(3) Antenna gain in dB is always a positive value. However, the value for any given azimuth can vary considerably from other azimuths. At microwave frequencies for links, high gain directional antennas are required. The main beam peak gain is often in the range of 30 dB to 40 dB. However, only a few degrees off the azimuth of the main beam, the gain is reduced considerably, to as much as -20 to -30 dB. It is essential that the radiation pattern specified by the antenna manufacturer be available for determining the gain in a particular azimuth.

Page 112 11/17/05 Chapter 12 - continued 6050.32B (4) Parabolic antenna gain calculations are approximated by a simple formula. Parabolic antennas are considered to be between 55 percent and 65 percent efficient. This general formula is for nonstandard size reflectors and for frequencies not commonly used for RCL and TML. A nomograph for parabolic antenna gains is found in appendix 4. Assuming the nominal 55 percent value, the gain would be:

G 20 log D + 20 log f + 7.5

dB = Where: G = gain over isotropic, in dBi dB f = frequency in GHz D = parabolic reflector diameter, in feet Assuming a 6 foot diameter reflector at 7.700 GHz, G = 15.56 + 17.73 + 7.5 = 40.79 dBi, or approximately 41 dBi (a) The forward gain of a high directional antenna is usually specified by the manufacturer in decibels above an isotropic antenna (dBi) or decibels above a dipole antenna (dBd), with dBd representing a value of 2.1 dB above dBi.

(b) The radiation pattern plot is usually shown in the manufacturer's instruction book or specification sheet. This plot may be polar or linear, but both are shown with the main beam at 0 dB and all side lobes shown as values less than the main beam reference gain value.

(c) The actual gain of the antenna at any given azimuth other than the primary main beam is that value shown on the plot for the selected azimuth subtracted from the rated main beam gain. For instance, a certain parabolic antenna is rated by the manufacturer at 43 dBd gain. The plot normally shows the main beam at 0 degrees, which represents the 43 dBd gain value. See figure 12-2. Use the HH plot, the upper solid line curve.

Looking at the plot at 15 degrees (the azimuth of the victim receiver), it is noted that at that azimuth, a minor lobe has a value of -37 dBd. Thus, the gain in the direction of 15 degrees from the azimuth of the main beam would be a value of 43 - 37 = 6 dBd. That value of 6 dBd is what is used as the "main beam" gain for subparagraph (3) above.

Page 113 6050.32B Chapter 12 – continued 11/17/05 FIGURE 12-2. TYPICAL PARABOLIC MICROWAVE ANTENNA RADIATION PATTERN e. It is necessary to calculate propagation loss as a parameter in assuring that the transmitter (Tx) power, the antenna gain, minus the free space loss, plus the receiver (Rx) sensitivity all add up to a usable path. This calculation is needed to determine the level of suspected signal in the vicinity of any competing user on the frequency engineered, for compatibility. Free space propagation loss is not obtainable on the earth, due to Page 114 11/17/05 Chapter 12 - continued 6050.32B atmospheric losses, reflections, etc. But using the basic free space propagation loss formula is as good an approximation as can be gained without actually putting a signal on the air and measuring it at the receiving location. That free space loss formula is:

L = 37.8 + 20 log f + 20 log d

fs (dB) where: L = free space loss, in dB fs f = frequency, in MHz d = distance in nmi (for statute miles, the constant 37.8 changes to 36.6) Assuming a 30 nmi path at 7700 MHz, L = 37.8 + 77.7 + 29.5 fs = 145 dB f. A nomograph for space loss is found in appendix 4.

g. From the receiver end , there are other parameters to be considered.

(1) The receiver minimum signal level required for satisfactory operation. This value should have already been determined by Technical Operations ATC Facilities in their siting study to assure adequate signal at the receiver at all times. This level is always a negative dBm value and is specified by the manufacturer.

(2) The receiver system interference susceptibility level is specified by the manufacturer in the system instruction manual or specification sheet. This value is usually in the form of a graph curve with dBm level on the y axis and frequency on the x axis. See Appendix 4 for typical curves. This value in dBm is the value that must ultimately be checked against the culprit's signal level at the victim receiver input terminals to determine whether RFI is anticipated.

(3) The receiving antenna gain in dB at the azimuth of the culprit incoming signal. That gain is determined in the same manner as for the transmitting antenna in subparagraph a. (3), above.

(4) The receiving wave guide (feed line) loss , always a negative value, in dB. This is determined from the wave guide or feed line manufacturer's specification sheet.

h. The path fade margin is the one variable in the parameters. It is the loss of signal level at the receiver from variable propagation losses, such as atmospheric moisture, air particle content, etc. The manufacturer of the system will specify the path margin normally required to assure adequate signal from the desired source to the desired receiver. While there is some variance among manufacturers and with frequency (higher bands are more subject to these path fade problems), a manufacturer frequently will specify a 10 dB fade margin. That is, under normal conditions, to assure that the minimum required signal is received by the desired receiver from the desired transmitter during path fade conditions, an additional level of protection is engineered into the siting of the units of the system. In this frequency compatibility study, however, a 15 dB D/U protection value shall be used which includes the path fade and other parameters not absolute. See figure 12-3.

Page 115 6050.32B Chapter 12 – continued 11/17/05 FIGURE 12-3. POWER BUDGET STUDY FOR A MICROWAVE LINK 1. Undesired transmitter power (+) _______ dBm 2. Undesiredt transmitter wave guide or feed line loss (–) _______ dB 3. Undesired transmitter antenna gain in the direction of the desired receiver. [1204 d.]

a. Main beam gain of the antenna (+) _______ dB b. Off-azimuth loss in the direction of the desired (–) _______ dB c. Total undesired antenna gain in the direction of desired (sum of a. and b. above) (±) _______ dB 4. Free space propagation loss. [1204 e.] (–) _______ dB 5. Desired receiver antenna gain in the direction of the undesired transmitter. [1204 g.]

a. Main beam gain of the antenna (+) _______ dB b. Off-azimuth loss in the direction of the undesired (–) _______ dB c. Total desired antenna gain in the direction of undesired (sum of a. and b. above) (±) _______ dB 6. Desired receiver wave guide or feed line loss (–) _______ dB ________________ 7. Undesired signal level at desired receiver input (TOTAL) (±) _______ dBm 8. Desired receiver RFI susceptibility level. [1204 g.] (–) _______ dBm 9. Difference between 7. and 8. (±) _______ dB The value of item 9 must be -15 dB or less (more negative) for interference-free operation of the link. A 15 dB safety margin, over and above all other calculations, should be provided for the receiver, to assure a positive D/U ratio under all conditions, including path fades.

Page 116 11/17/05 Chapter 12 - continued 6050.32B i. Desired versus Undesired . When engineering a link frequency for FAA, the FAA transmitter is the "undesired" culprit. All other receivers in place within RLOS (or at least 40 nmi) and within frequency range must be checked as the "desired" or victim. When checking the FAA receiver situation, any other system transmitter within the same bounds is the culprit. For both situations, FAA as a victim and a culprit, adequate protection must be shown before the frequency(ies) can be submitted to Technical Operations ATC Spectrum Engineering Services for approval. If another agency is proposing a new system and an FAA system is within interference bounds, the other agency must assure protection. In some bands, that agency is required to coordinate with the FAA to verify protection assurance. Even in the bands not requiring FAS coordination notices, verify before approving or coordinating the proposal.

j. The most practical method to accomplish the study is to use these tools: (1) A topographical or sectional map permits plotting and verification of the systems accurately by coordinates. It is then easy to draw a straight line between the two systems and measure the azimuth deviation from the respective antennas' azimuths heading for their own system.

(2) The AFM CIRCLE program will permit quick and easy access to all systems within the frequency and distance ranges desired for the study.

(3) The AFM bearing/distance program will also provide quick and accurate azimuths and distances between culprit and victim sites.

(4) Note that the final selection of the frequency(ies) may depend on terrain factors which are not easily quantified but which may be apparent from a site survey or analysis of a topographical map.

(5) Use the format of figure 12-3 to determine the power budget and the D/U ratio.

k. Many FAA microwave systems use digital radios . It should be noted that nominally up to 10 dB of additional margin may be required for digital receivers as compared to an equivalent analog receiver.

1205. FREQUENCY ENGINEERING FOR THE 932-935 AND 941-944 MHZ BANDS .

Engineering of LDRCL in these bands is straightforward. The channeling plans for these bands and other constraints on their use are found in NTIA Manual, Chapters 4 and 5. Cosite and intersite engineering will utilize procedures found in paragraph 1204, as well as criteria in NTIA Manual, Chapters 4 and 5.

1206. FREQUENCY ENGINEERING FOR THE 1710-1850 MHZ BAND . As directed by Title VI of the Omnibus Budget Reconciliation Act of 1993 (OBRA-93), Title III of the Balanced Budget Act of 1997 (BBA- 97), and the Strom Thurmond National Defense Authorization Act for Fiscal year 1999 (NDAA-99), the 1710- 1755 MHz portion of this band will be auctioned and transferred to the private sector. Therefore, there will be no further FAA assignments in the 1710-1755 MHz band. No standard frequency plan exists for this band. Refer to Paragraph 1204 for a general analysis of microwave link engineering.

a. Cosite frequency engineering .

(1) Transmitter-to-transmitter (Tx/Tx) frequency separation shall be at least 30 MHz.

(2) Transmitter-to-receiver (Tx/Rx) frequency separation shall be at least 40 MHz.

(3) Receiver-to-receiver (Rx/Rx) frequency separation shall be at least 15 MHz.

Page 117 6050.32B Chapter 12 – continued 11/17/05 b. Intersite frequency engineering . To assure that other microwave systems in the area do not cause interference (or in order to determine that FAA systems will not cause interference to other agencies' systems), the following procedure shall be used.

(1) Using the AFM CIRCLE program , determine all microwave systems within at least 60 nmi of the proposed site.

(2) Using the AFM bearing/distance program , and taking into account the beam widths of the respective transmit and receive antennas, determine all microwave systems which could be an interference source or victim of the proposed site.

(3) Using the procedure given in figure 12-3, determine whether potential interferers or victims should be further analyzed.

1207. FREQUENCY ENGINEERING FOR RCL IN THE 7125-8500 MHZ BAND . This process consists of two separate criteria. The first considers the FR8 equipment requirements. Note that the FR8 equipment is limited to 7125-8400 MHz. The second concerns microwave link general engineering and is discussed in paragraph 1204.

a. Cosite frequency engineering .

( 1) The FR8 equipment frequency selection criteria consists of seven tests. These test apply to the Tx's and Rx's using a common wave guide and antenna configuration.

Test 1. Space bands - must be located outside of bands 7250-7300 and 7900-8025 MHz.

Test 2. Rx local oscillator (LO) - must be within the band 7125-8400 MHz.

Test 3. Tx/Tx and Rx/Rx separation - a minimum of 60 MHz.

Test 4. Tx/Rx separation - Tx frequency must have at least 80 MHz separation from the Rx input frequency. If the Rx is at 8200, then a Tx is not permitted between 8120-8280, based on this test.

Test 5. Image frequency protection - For a 1 W Tx , the Tx output frequency must have at least 30 MHz separation from the image frequency; i.e., if the Rx is at 8200 and the Rx LO at 8270, then the Rx image frequency is 8340. The Tx must then not be within the 8310-8370 range, based on this test. For a low side Rx LO at 8130, the Rx image frequency is 8060. A Tx is not permitted within the 8030-8090 range, based on this test. For a 5 W Tx , the Tx output frequency must have at least 45 MHz separation from the Rx image frequency. If an enhanced Rx RF input is installed , both 1 W and 5 W Tx's output frequency must have at least 15 MHz separation from the Rx image frequency.

See figure 12-4.

Test 6. The transmitter local oscillator (Tx LO ) must be >30 MHz from other Rx(s) within the hop.

NOTE: TX LO = RX LO, i.e. TX = 8270, TX LO = 8270; no other RX permitted between 8240-8300.

Test 7. For a 1 W Tx , a third-order intermodulation products frequency is not permitted within 15 MHz of the Rx input frequencies. For a 5 W Tx , a third-order intermodulation products frequency is not permitted within 30 MHz of the Rx input frequencies.

Page 118 11/17/05 Chapter 12 - continued 6050.32B FIGURE 12-4. EXAMPLE OF TESTS 4 AND 5 PROHIBITED ZONES ( 2) Once the 7 tests in subparagraph (1) above have been satisfied for the Tx's and Rx's on a common antenna, the back-to-back coupling must be considered. Back-to-back coupling is the fraction of power received by a second antenna located on the same tower but facing in a different direction from the Tx antenna and using a separate wave guide. The following specifications assume an angular azimuth separation of at least 15 degrees.

(a) For a 1 W Tx with a standard antenna , the Tx output frequencies must be separated from other cosite Rx frequencies by at least 40 MHz.

(b) For a 5 W Tx with a standard antenna , 45 MHz.

(c) For a 1 W or 5 W Tx with a high performance antenna , 25 MHz.

b. Intersite frequency engineering . Use the same procedure as described in paragraph 1204.

(1). The antenna front-to-back ratio must also be considered. That ratio is defined as the ratio of the power transmitted by the front side of the antenna to the power transmitted by the back. For a 1 W or 5 W Tx with a standard antenna, the transmitted frequencies must be separated from other cosite frequencies by at least 30 MHz; with a high performance antenna , 10 MHz.

(2) The standard RCL frequency family is shown in figures 12-5 and 12-6.

(3) The preferred LO frequency is indicated following the operating frequency. The "+" indicates the LO is on the high side of the operating frequency, the "—", the low side.

Page 119 6050.32B Chapter 12 – continued 11/17/05 FIGURE 12-5. STANDARD RCL FREQUENCY FAMILY FOR 7125-8400 MH z Direction A Direction B A. 7160 + 7340 —* 7430 + 7605 — B. 7205 + 7385 —* 7475 +* 7650 — C. 7185 + 7365 + 7695 —** 7630 + D. 7230 + 7135 + 7495 — 7580 + D. 7230 + 7320 —* 7495 +* 7580 — E. 7685 — 7805 + 8170 + 8290 — E. 7685 — 7805 + 8170 + 8045 + F. 7745 + 7865 — 8230 — 8350 — F. 7745 + 7865 — 8230 — 8105 + G. 7725 + 7845 — 8210 + 8330 — G. 7725 + 7845 — 8210 + 8085 + H. 7785 + 8270 — 8145 — 8390 + J. 7765 + 7885 — 8250 — 8370 — J. 7765 + 7885 — 8250 — 8125 + K. 7705 + 7825 + 8190 + 8310 - K. 7705 + 7825 + 8190 + 8065 + Notes: (1) * Indicates a "flopped" LO. This option was not initially manufactured for this LO, but it can be ordered.

(2) ** Indicates a new frequency, not previously assigned to the RML standard family.

(3) Direction A or B is a set of Tx's and Rx's in one direction of a hop.

(4) Before using the above sets of frequencies together within the same link or on parallel links, they must be checked for back-to-back and front-to-back separations.

(5) The table does not assume or imply exclusive FAA use.

(6) See figure 12-6 for examples of selection and tests. Frequencies are taken from the standard chart. Test 4 results show Tx frequencies do not fall on critical frequencies. Test 5 results show Tx frequencies fall outside image band plus separation band.

(7) The symbols "+" or "—" indicate that the preferred LO is located on the high or low side of the operating frequency, respectively.

Page 120 11/17/05 Chapter 12 - continued 6050.32B FIGURE 12-6. SAMPLE OF FREQUENCY SELECTION, TEST 4 AND 5 -----------Test 4 ---------- --------> Tx 7160 + Rx 1 = 7430 Rx 2 = 7605 --------> Tx 7340 — -80 +80 <-------- Rx 7430 + 7350 7685 <-------- Rx 7605 — (image is on the opposite side) ----------Test 5----------- Tx 1 = 7430 + Rx 2 = 7605 — (Image band 140 MHz) +140 -140 (30 MHz reqd sep.) + 30 -30 7600 7435 c. Hybrid frequency/space diversity . See paragraph 1211.

1208. FREQUENCY ENGINEERING FOR LDRCL IN THE 7125-8500 MHZ BAND . This considers the ALCATEL MDR-6000 equipment requirements.

a. Cosite frequency engineering.

(1) The ALCATEL equipment frequency selection criteria consists of 6 tests. These tests apply to the Tx's and Rx's using a common wave guide and antenna configuration.

Test 1. Space bands - must be located outside of bands 7250-7300 and 7900-8025 MHz.

Test 2. Rx local oscillator (LO) - must be within the band 7125-8500 MHz.

Test 3. Tx-to-Tx frequency separation must be 46 MHz or greater.

Test 4. Rx-to-Rx frequency separation must be 46 MHz or greater.

Test 5. Tx-to-Rx frequency separation . The Tx frequency must have at least 115 MHz separation from the Rx input frequency.

Test 6. A third-order intermodulation product is not permitted within 15 MHz of the Rx input frequency.

(2) Once the 6 tests in subparagraph (1) above have been satisfied for the Tx's and Rx's on a common antenna, the back-to-back coupling must be considered. Back-to-back coupling is the fraction of power received by a second antenna located on the same tower but facing in a different direction from the Tx antenna and using a separate wave guide. The following specifications assume an angular azimuth separation of at least 15 degrees.

(a) It is recommended that the Tx output frequencies must be separated from the other cosite frequencies by at least 33 MHz.

Page 121 6050.32B Chapter 12 – continued 11/17/05 b. Intersite frequency engineering . Use the same procedure as described in paragraph 1204.

c. Hybrid frequency/space diversity . See paragraph 1211.

1209. FREQUENCY ENGINEERING FOR THE 14.5000-14.7145 AND 15.1365-15.3500 GHZ BANDS.

a. Cosite frequency engineering is unnecessary. FAA only uses this band for one-way links to support Digital Bright Radar Indicator Tower Equipment (DBRITE).

b. Intersite frequency engineering . This frequency band and associated equipment are normally limited to a 20 mile one-way path with not more than two repeaters. See paragraph 1204.

c. The frequency family plans are shown in figures 12-7.

d. The TML equipment frequency coverage limitation prohibits use of the TML equipment between 15.25-15.35 GHz.

Page 122 11/17/05 Chapter 12 - continued 6050.32B FIGURE 12-7. CURRENT TML CHANNELIZATION PLAN MHz MHz MHz MHz 14501.25* 15141.25* 14606.25 15246.25 14503.75 15143.75 14608.75 15248.75 14506.25 15146.25 14611.25 15251.25** 14508.75 15148.75 14613.75 15253.75** 14511.25 15151.25 14616.25 15256.25** 14513.75 15153.75 14618.75 15258.75** 14516.25 15156.25 14621.25 15261.25** 14518.75 15158.75 14623.75 15263.75** 14521.25 15161.25 14626.25 15266.25** 14523.75 15163.75 14628.75 15268.75** 14526.25 15166.25 14631.25 15271.25** 14528.75 15168.75 14633.75 15273.75** 14531.25 15171.25 14636.25 14276.25** 14533.75 15173.75 14638.75 15278.75** 14536.25 15176.25 14641.25 15281.25** 14538.75 15178.75 14643.75 15283.75** 14541.25 15181.25 14646.25 15286.25** 14543.75 15183.75 14648.75 15288.75** 14546.25 15186.25 14651.25 15291.25** 14548.75 15188.75 14653.75 15293.75** 14551.25 15191.25 14656.25 15296.25** 14553.75 14193.75 14658.75 15298.75** 14556.25 15196.25 14661.25 15301.25** 14558.75 15198.75 14663.75 15303.75** 14561.25 15201.25 14666.25 15306.25** 14563.75 15203.75 14668.75 15308.75** 14566.25 15206.25 14671.25 15311.25** 14568.75 15208.75 14673.75 15313.75** 14571.25 15211.25 14676.25 15316.25** 14573.75 15213.75 14678.75 15318.75** 14576.25 15216.25 14681.25 15321.25** 14578.75 15218.75 14683.75 15323.75** 14581.25 15221.25 14686.25 15326.25** 14583.75 15223.75 14688.75 15328.75** 14586.25 15226.25 14691.25 15331.25** 14588.75 15228.75 14693.75 15323.75** 14591.25 15231.25 14696.25 15336.25** 14593.75 15233.75 14698.75 15338.75** 14596.25 15236.25 14701.25 15341,25** 14598.75 15238.75 14703.75 15343.75** 14601.25 15241.25 14706.25 15346.25** 14603.75 15243.75 14708.75* 15348.75** * These frequencies cannot be used for bandwidths greater than 2.5 MHz.

Total number of channels is 168.

** Due to TML equipment limitations, these frequencies are not usable.

From the radar end, use a 14 GHz frequency. If a repeater is necessary, use the paired 15 GHz frequency for the repeater. If another repeater is required, use another 14 GHz frequency; do not exceed two repeaters.

Page 123 6050.32B Chapter 12 – continued 11/17/05 1210. FREQUENCY ENGINEERING FOR LDRCL IN THE 21.2-23.6 GHZ BAND . This band has a very short propagation characteristic and can be optimally engineered by assuring that cochannel operations are not within 10 nmi. The frequency plan for LDRCL in this band is shown in figure 12-8.

a. Cosite frequency engineering . For cosite operation, ensure a Tx-Rx frequency separation of at least 1.2 GHz and a Tx-Tx frequency separation of at least 50 MHz.

b. Intersite frequency engineering . See paragraph 1204, except limit search to RLOS.

FIGURE 12-8. 21.2-23.6 GHZ LDRCL FREQUENCY ASSIGNMENT PLAN Freq 1 Paired with Freq 2 (GHz) (GHz) 21.225 22.425 21.275 22.475 21.325 22.525 21.375 22.575 21.425 22.625 21.475 22.675 21.525 22.725 21.575 22.775 21.625 22.825 21.675 22.875 21.725 22.925 21.775 22.975 21.825 23.025 21.875 23.075 21.925 23.125 21.975 23.175 22.025 23.225 22.075 23.275 22.125 23.325 22.175 23.375 22.225 23.425 22.275 23.475 22.325 23.525 22.375 23.575 1211. SPECIAL PATH CONSIDERATIONS . Although the problem occurs most often on the southern portions of the east and west coast of the contiguous United States and Hawaii, varying path propagation can present real difficulties. There are two ways to alleviate the problem. One is space diversity and the other is frequency diversity. Because space diversity takes no additional frequencies, it is preferable. See figure 12-9.

In addition, for digital systems, a hybrid combination of both space and frequency diversity can be provided.

See subparagraph c.

Page 124 11/17/05 Chapter 12 - continued 6050.32B FIGURE 12-9. SPACE DIVERSITY a. Space diversity is an effective method to counter multipath fading. It relies on the height dependence of the maxima and minima of the multipath interference patterns. By using the combined or switched output of two antennas separated vertically by many wavelengths, significant improvement can be achieved.

(1) If the antennas have sufficient separation , fades on one path will be accompanied by an enhanced signal on the other path. Vertical antenna separation of 30 to 35 feet for RCL and 25 to 35 feet for TML should be adequate. Best performance will be obtained if the second antenna is placed directly above the original clear path antenna. However, tower height restrictions or costs may prohibit this option.

(2) Satisfactory performance can usually be obtained when the spacing between antennas is split above and below the original clear path. In this case, it will be necessary to check for problems due to nearby obstacles close to the lower antenna path to assure a still clear path.

(3) To have space diversity in one direction of the link, the spaced antennas are associated with the Tx's.

For more severe fading problems, spaced antennas are placed at both ends of the link.

FIGURE 12-10. FREQUENCY DIVERSITY b. The RCL and LDRCL use frequency diversity. A diagram of such a system is shown in figure 12-10.

Page 125 6050.32B Chapter 12 – continued 11/17/05 c. A hybrid system of combined frequency/space diversity for digital systems for the 7125-8500 MHz band also can be provided.

(1) In a hybrid diversity configuration , one antenna is installed at one end of the path (Site A) and two antennas are installed at the other end of the path (Site B). Two different frequencies are transmitted from the common antenna at Site A and they are received on the two different antennas at Site B. As a result, the direction of transmission from A to B is similar to normal space diversity. In the reverse direction, one frequency is transmitted from the top and the other from the bottom antenna. Both frequencies are received at the common antenna Site A and switched to the appropriate receiver.

(2) In both directions of transmission, there is a physical separation between the propagation paths.

There is a true space diversity improvement in both directions. Since the different paths also operate at different frequencies, there is also frequency diversity improvement.

(3) Cosite frequency engineering for the digital hybrid system is different from analog engineering.

(a) Transmitter to transmitter (Tx/Tx) frequency separation shall be equal to or greater than 50 MHz.

(b) Receiver to receiver (Rx/Rx) frequency separation shall be equal to or greater than 50 MHz.

(c) Transmitter to receiver (Tx/Rx) frequency separation shall be equal to or greater than 115 MHz.

FIGURE 12-11. HYBRID FREQUENCY/SPACE DIVERSITY 1212. PATHS WITH PASSIVE REFLECTORS . Reflectors are a way to direct the beam path to where it is needed while avoiding obstructions, or where considerable height is needed to avoid a long wave guide run.

Page 126 11/17/05 Chapter 12 - continued 6050.32B a. A periscope antenna is shown in figure 12-12. A parabolic antenna is positioned to beam upwards to illuminate a passive reflector at the top of the tower. This avoids problems and costs associated with long runs of wave guide with minimal change in net gain. When properly designed, only first Fresnel zone energy is reflected, thus avoiding phase cancellation from the out-of-phase second zone energy. The design produces a sharper beam with 2 or 3 dB gain.

FIGURE 12-12. PERISCOPE OR TOP REFLECTOR ANTENNA SYSTEM FIGURE 12-13. SINGLE BILLBOARD PASSIVE ANTENNA Page 127 6050.32B Chapter 12 – continued 11/17/05 FIGURE 12-14. DOUBLE BILLBOARD PASSIVE ANTENNA b. Billboard passive repeaters are used for links where terrain, foliage or man-made obstacles prevent a direct RLOS between desired sites. Figure 12-13 depicts single and figure 12-14 depicts double billboard configurations. Here again, both the original and reflected paths must be considered, both for satellite conflict and for the possibility of line-of-sight interference to another user on the same path. That is, not only the billboard reflected path must be checked, but also the azimuth "direct" path of the transmitted signal as it points at the billboard reflector. In Figure 12-13, that is the Tx/Rx azimuths between the billboard tower and the foreground tower as well as the azimuths through the mountains path.

1213. MAPPING .

a. Link systems can become very complex, particularly if there are repeaters, or if any reflectors are used.

Research for any new FAA systems must first look at other FAA and other systems to assure compatibility. It is necessary to establish some form of maps on which to plot all regional systems.

b. The format is not specified, but some form of map records for all regional link system shall be maintained. Aeronautical sectional or local maps are excellent, because they have accurate coordinates on them, and make plotting of sites easy.

1214. thru 1299. RESERVED .

Page 128 (thru 136)

11/17/05 6050.32B CHAPTER 13. RADAR AND AIR TRAFFIC CONTROL RADAR BEACON SYSTEM (ATCRB S) FREQUENCY ENGINEERING 1300 . POLICY . Technical Operations ATC Spectrum Engineering Services completes all initial frequency engineering for new radar systems. The regional FMO completes subsequent frequency changes as a result of RFI or relocations, modifications, five/ten year reviews, and coordination of other agencies requests to transmit in the radar frequency bands.

a. FAA is designated by NTIA as the national coordinator for 1030/1090 MHz and the 1215-1390 MHz, 2700-2900 MHz and 9000-9200 MHz bands. As national coordinator, all users must coordinate with the FAA for systems in these bands. Upon coordinating with a field user of these systems, the service area FMO will enter a coordination record into the automated frequency management (AFM) system pending database to "reserve" the frequency for the user. These coordinated requirements will be forwarded to Technical Operations ATC Spectrum Engineering Services by setting the status of the record to “MN”. Technical Operations ATC Spectrum Engineering Services will review these records, make any necessary changes to the proposed operation, and then set the record to a status of “MA” to indicate the concurrence of Technical Operations ATC Spectrum Engineering Services. Once the record is set to “MA” status, the regional FMO can then pass on to the field user the FAA’s concurrence along with any necessary changes or restrictions to the proposed operation. The coordinated record will be purged from the pending database once the assignment has been registered in the Government Master File.

b. FAA, as Chair of the AAG , is also responsible for the proper engineering and management of the 1030/1090 MHz pair. Upon coordination with users for new requirements on these frequencies, the FMO will enter a coordination record, as is done for the above radar bands, in order to reserve the frequency and the PRR.

(1) All Mode-S systems require a Site Identification (ID), or II code assigned. Using the properly assigned Site ID code is critical to prevent aircraft from being locked out from responding to other interrogations.

Requests to use Mode-S will be forwarded to Technical Operations ATC Spectrum Engineering Services, who will engineer a Site ID.

(2) All Mode-4 requests will be forwarded to Technical Operations ATC Spectrum Engineering Services for support. The DOD uses Mode-4 when interrogating on 1030 MHz to determine if an aircraft is friendly. This mode of operation, however, suppresses civil transponders preventing civil aircraft from responding to legitimate interrogations by air traffic control. Caution must be exercised before approving any use of 1030 MHz by the military to ensure that the military will not be operating in Mode-4. Mode-4 operations are often indicated by a pulse duration of 0.5 microseconds as opposed to the standard ATCRBS 0.8 microseconds. If the use of Mode-4 is required, the request should be forwarded to Technical Operations ATC Spectrum Engineering Services.

c. Next Generation (NEXRAD) (WSR-88D) and Terminal Doppler Weather Radar (TDWR) systems operate in the 2700-3000 MHz and 5600-5650 MHz band respectively. All new frequencies to support these systems will be engineered by Technical Operations ATC Spectrum Engineering Services. The service area FMO will still do five-year reviews and any necessary modifications to these frequency assignments.

d. Airport Surface Detection Equipment (ASDE) models X and 3 operate in the 9.0-9.2 GHz and 15.7-16.2 GHz band respectively. Technical Operations ATC Spectrum Engineering Services will engineer all new frequencies to support these systems. The service area FMO will still do five-year reviews and any necessary modifications to these frequency assignments.

Page 137 6050.32B Chapter 13 – continued 11/17/05 1301 . GENERAL ASSIGNMENT PROCEDURES .

a. The selection of a frequency for an Air Route Surveillance Radar (ARSR) that operates in the 1215- 1390 MHz band, or Airport Surveillance Radar (ASR) that operates in the 2700-2900 MHz band, is similar to the problem of squeezing a COMM or NAVAID facility into an already crowded spectrum. The major difference is the large bandwidths and power required. For instance, an ARSR-1 or ARSR-2 has an emitted spectrum that extends considerably beyond the –20 dB bandwidth that is defined in the emission designator. Although the spectrum beyond the –20 dB bandwidth is over 40 dB suppressed and meets the NTIA standard, that broad spectrum can be a problem to adjacent channel users.

b. Radar receivers also have a decided effect on the assignment process. Even though a receiver may seem to have a band pass that is extremely wide by COMM or NAVAID standards, the narrowest band pass possible is implemented to detect the weak return signals required for radar reception. If it is an established radar system, it must be protected by any assignment of a new facility.

c. Most radars have two separate transmitters and receivers, although some radars operate only one transmit and receive (T/R) channel at a time. The other channel is normally tuned to another frequency and is used as a backup or an alternate system. For interference protection and to realize the benefits of frequency diversity, it is desirable to separate the two frequencies as far as possible within the band. While as much frequency separation as possible is the goal, in most areas of the country, frequency congestion is so severe that the two channels must be assigned frequencies with only a few MHz of frequency separation. Since the unused channel is kept "hot," some frequency separation is necessary to prevent interference to the operating channel.

d. Diplex radars operate both channels simultaneously, although their actual transmitting time is usually separated in time so that the transmitted pulse of one is off while the transmitted pulse of the other is firing.

The difficulty for the FMO is that a minimum frequency separation between the two channels is required (see paragraphs 1304-1308 for individual radar's minimum frequency separation).

e. The pulse repetition rate (PRR) is the number of pulses of energy per second (pps) transmitted by the system and normally is the trigger for the associated ATCRBS interrogator.

f. The pulse repetition time (PRT) is that time in microseconds (usec) between the start of any two consecutive radar pulses. In numerical terms, PRT = 1/PRR and PRR = 1/PRT.

g. Radar Beacon Systems have changed over time from the original concept of simple detecting and ranging. The addition of a nondirectional but lower power simultaneously transmitting set of pulses has been used to reduce false targets caused by various sources. The system is called Side Lobe Suppression (SLS), and a later version, Improved SLS (ISLS). With the implementation of Specialized ATCRBS with discrete address capability (Mode S) and other monopulse radars, "sum and difference" patterns on the directional antenna are being used to enhance accuracy.

h. Other devices such as a Beacon False Target Eliminator (BFTE) and a "defruiter" to eliminate electronically undesired responses called False Returns Unsynchronized In Time (FRUIT) have had varying degrees of success. Newer versions that include Mode-S capability allow beacon systems to access a single aircraft through selective addressing.

i. The FMO also should be aware of airborne radar and altimeter frequency bands, such as 4200- 4400 MHz, 5350-5470 MHz, 9300-9500 MHz and 13.25-13.45 GHz. From time to time, the FMO may be asked to assist in elimination of RFI for such systems.

Page 138 11/17/05 Chapter 13 - continued 6050.32B 1302. PRR ASSIGNMENT OF ATCRBS .

a. The ATCRBS is the heart of the entire NAS surveillance system. Unfortunately, ATCRBS operates through a single pair of frequencies: 1030 MHz (ground-to-air) and 1090 MHz (air-to-ground). The only method for discriminating between each ATCRBS facility is by the PRR (noting that ATCRBS PRR is really interrogations per second and not pulses per second). It is only through the use of different PRRs that all these systems can operate simultaneously. Since all the military IFF systems also operate on the same frequency pair, the critical task of engineering individual PRRs can be readily understood.

b. The best current method to keep PRRs from interfering with one another is to use a staggered PRR. It works on the basis of a crystal controlled clock generating a fixed time base. Prearranged programming selects a PRT in sequence, followed by another but different period, and so on for 4, 5, 6 or 7 periods before repeating the whole sequence. Each such stagger system has several stagger groups. By staggering PRRs, the chance of hitting the exact time of an emitted pulse of another 1030 MHz interrogator is enormously decreased. The stagger sequence for ARSRs and ASRs and their associated ATCRBS are shown in various figures in later paragraphs and tables.

c. The necessity for separating PRRs is that should two interrogators transmit at the same PRR and both illuminate the same aircraft simultaneously, both radars will receive both reflections and produce a real and a false target, separated by the time and azimuth difference between the two reflections.

d. ATCRBS is normally associated with FAA ASR and ARSR radars, but at times, ATCRBS is a stand- alone system. ATCRBS also has been called Secondary Radar (SECRA), Secondary Surveillance Radar (SSR), Radar Beacon (Beacon), interrogator (ground), transponder (aircraft) and the military versions Identification, Friend or Foe (IFF) and the DOD Selective Identification Feature (SIF) modified IFF. In ATC functions, the ATCRBS is sometimes tied to a primary radar and its PRR is equal to or a submultiple of the primary's PRR. In the case of staggered PRR, there is a basic clock relationship between the primary radar and the interrogator.

e. There are a number of problems which may be considered as "interference" in the broad sense. The FMO must be aware of them and their consequences as part of the PRR selection process and interference reporting.

(1) Ringaround is an aircraft transponder being interrogated by antenna side lobes causing elongated targets on the radar scope, as shown in figure 13-1. The effect is reduced or eliminated by sidelobe suppression (SLS).

(2) False targets can be caused by either synchronous airborne replies to another beacon or reflections of the main beam energy. Aircraft transponders can reply to more than one interrogator and thus the beacon ground system can receive signals with various PRRs. A defruiter will eliminate nonsynchronous PRR FRUIT, but it will not reject synchronous PRR replies, so that false targets may appear on the display. This problem can best be controlled by geographical separation of similar PRR beacon systems. False targets are also caused by reflections of the main beam signal off large metal objects (e.g., a hangar), such that an aircraft outside the main beam is interrogated (see figure 13-2). SLS and interrogator power reduction will help reduce this phenomenon. (See Orders 6310.6, Primary/Secondary Terminal Radar Siting Handbook; 6340.15, Primary/Secondary En Route Radar Siting Handbook; 6360.12, ATCRBS Performance Handbook.)

(3) "Second time around" signals are those which show up on the scope even though they are beyond the distance of the actual target. It is caused by the interrogator signal going beyond its intended range and being received during the "next" receive pulse period of the radar, thus showing in the designed range, but actually being at a much greater distance. Various stagger and other fixes have eliminated most of this problem, but it does occur on occasions.

Page 139 6050.32B Chapter 13 – continued 11/17/05 (4) Broken or serrated targets can be caused by synchronous PRR and by overinterrogation, causing reduction in sensitivity such that only the strongest interrogation will be answered. It is best controlled by low PRR assignments, proper PRR separation, and interrogator power reduction.

(5) Defective responses can plague the FMO which are not actual interference from another source.

The ability to diagnose the difference is an art that comes from training and experience. Technical Operations ATC Spectrum Engineering Services can supply data. A good information source is the radar engineering group in the service area office.

FIGURE 13-1. DISPLAY TIME EXPOSURE FOR A RADIAL FLIGHT SHOWING RINGAROUND Page 140 11/17/05 Chapter 13 - continued 6050.32B FIGURE 13-2. DISPLAY VIEW OF A REAL AND A FALSE TARGET f. From the radar engineer's perspective , the highest possible PRR is desirable so that the hits-per-scan can be high. That function is an important parameter in radar operation. But from the FMO's view, the lowest PRR is ideal, to keep the ATCRBS spectrum as free from congestion as possible.

g. Care must be taken to separate assigned PRRs by a sufficient amount to assure noninterference. This is really a function of time and thus is a pulse period variant. But in the 350-370 pps non-stagger range of the ARSR-1 and -2, a PRR difference of 5 pps is sufficient. The standard PRRs for these radars are 350, 355, 360, 365 and 370 pps. Non-stagger radar beacons associated with ASR types normally use a PRR from 323-400 pps, e.g., ASR-8.

h. The same frequency pair (1030/1090 MHz) is also used by DOD IFF/SIF. But many of their older radars have PRRs that come out in odd numbers and decimals, due to the multivibrator oscillators used to generate the PRR. There is another problem with that type of radar. Besides drifting some because it is not crystal controlled, such military radars operate on harmonics of the oscillator. As a result, PRR can be transmitted at a much higher or lower rate than authorized, if the Nth harmonic is inadvertently tuned up. This has happened in the past. Hopefully, this will gradually diminish as old radars are phased out and newer stable and staggered PRRs are introduced in the new equipment.

1303. PRR ASSIGNMENT PROCESS . There is a series of procedures and precautions involved in making a new or modified PRR assignment.

a. The FAA is designated by the NTIA as the national coordinator for the 1030/1090 MHz frequency pair.

This includes DOD as well as non-Federal users. Non-Federal users include contractors developing and testing radars for the Federal Government. All non-Federal assignments and any DOD assignment that is not being used exclusively for air traffic control are considered experimental.

b. New PRR requests require careful review of the location, equipment type, and PRR parameters requested.

This will consist primarily of consulting the geographic/PRR list retained in the FMO's office, following the steps Page 141 6050.32B Chapter 13 – continued 11/17/05 outlined in paragraph “d” below, and utilizing these guidelines: (1) When a PRR is engineered for a non-FAA requestor , the requestor shall be advised of the FMO's recommended PRR. The requestor's IRAC or FCC application must show that coordination has been effected with the FMO.

(2) When a PRR is engineered for an FAA facility , an IRAC application will be filed in the usual manner.

(3) If a suitable PRR is not found , the FMO shall notify the requestor of the problem, advising the requestor that it will be necessary to adjust parameters so that another search may be made. To the extent possible, the FMO should offer suggestions about what parameters can be changed to allow a PRR to be assigned.

Advise Technical Operations ATC Spectrum Engineering Services if no PRR can be found.

c. The national standard maximum PRR is 450 pps and must not be exceeded.

d. Interrogator PRR Engineering procedures : (1) Beacon paired with a primary radar : (a) The first step in engineering a beacon PRR is to determine what PRRs the beacon system is capable of accepting. If the beacon uses a staggered PRR, get the stagger sequences that the system is capable of.

(b) The second step is to find the average PRT if the system is staggered. If the system has only a single fixed PRR, then skip this step; otherwise, you have to calculate the average PRR. If the stagger rates are expressed as PRRs (i.e a four time stagger of 223/320/267/350), then each PRR will need to be converted to a PRT (1/PRR), the PRTs added up, divided by the number of PRRs in the stagger sequence, take the reciprocal of the quotient, and then multiply by (1 X 10 ). For example, using the four time stagger sequence provided in the example above: 1/223 = .0044843, or 4484.3 usec 1/320 = .0031250, or 3125.0 usec 1/267 = .0037453, or 3745.3 usec 1/350 = .0028571, or 2857.1 usec 4484.3 + 3125.0 + 3745.3 + 2857.1 = 14211.7 usec 14211.7 / 4 = 3352.925 usec 1 / 3352.925 = .000298247 (1 X 10 ) = 298.247 average Pulses Per Second Note: The average PRR is not calculated by just adding the PRRs and dividing by the stagger rate.

(c) The third step is to determine whether the new interrogator is an ARSR-4 (250 nmi), en route (200 nmi), or a terminal (60 nmi) facility.

(1) ARSR-4 facilities shall be assigned PRTs that differ by at least 25 usec from any other ARSR-4 facility within 500 nmi, from any other en route facility within 400 nmi, and any terminal facility within 350 nmi.

Page 142 11/17/05 Chapter 13 - continued 6050.32B (2) En route radars shall be assigned PRTs that differ by at least 25 usec from any other en route facility’s PRT within 360 nmi, and terminal facilities within 300 nmi. At least 25 usec of PRT separation needs to be maintained between the enroute radar and any ARSR-4 within 400 nmi.

(3) Terminal radars shall be assigned PRTs that differ by at least 25 usec from any other terminal facility’s PRT within 200 nmi, en route facilities within 300 nmi, and ARSR-4 facilities within 350 nmi..

NOTE : For radar systems that use a staggered PRR, use the PRT of the average PRR as calculated in the second step above. It is this PRT that you base the 25 usec of separation on - not each PRT in the stagger sequence.

(4) A stand-alone beacon uses the same procedure. Just base the 25 usec separation criteria on the range of the beacon.

e. ATCRBS or IFF/SIF interrogator power must be reduced to the lowest possible level. The higher the power, the more aircraft are interrogated and generate replies, cluttering the ATCRBS environment. In practice, it has been found that 60 to 100 W is sufficient for most 60 nmi terminal systems. The maximum permissible power that can be used by en route radars such as the ARSR series is 52.5 dBW (approximately 1,500W).

However, with the advent of the FAA William J. Hughes Technical Center (FAATC) Dipole Feed (NADIF) antenna and later other models, a power of only 250 W will still provide good system coverage while reducing overinterrogation of the system. DOD IFF/SIF systems frequently try to use 500 to 1,000 W. The FMO must ensure that only the minimum power needed to do the job is all that is used, whether it is associated with ARSR, ASR, DOD radar or stand-alone. A minimum signal level of –74 dBm is all that is needed to interrogate an aircraft transponder.

f. Special care must be taken when dealing with some DOD radars whose antennas have very broad beam widths. Some systems, particularly older models or those used in training have small antennas for portability.

This helps them in rapidly moving the equipment around, but unfortunately the result of the smaller antenna is a much broader beam width. Instead of 1 Ε or 2 Ε maximum beam width of FAA ATCRBS antennas, some of the older military portable units have as much as 8 Ε beam width. This multiplies the number and duration of interrogations of aircraft, adding unnecessary congestion. NTIA does not yet have antenna beam width standards (see NTIA Manual).

g. DOD training maneuvers may present the FMO with interference problems. While the FMO does not have the authority to specify beam widths, NTIA requires that the FMO be advised when maneuvers are to be held in an FMO's service area. An alert is thus received to the possibility of ATCRBS interference through overinterrogation. The FMO will coordinate the DOD training radar usage, e.g., power, PRR, etc., and seek the advice of Technical Operations ATC Spectrum Engineering Services as needed. If the DOD is requesting to use Mode-4, then forward the request to Technical Operations ATC Spectrum Engineering Services for support. In the event of an actual problem of this kind, the FMO shall immediately contact the appropriate DOD AFC and Technical Operations ATC Spectrum Engineering Services.

h. Radar Beacon Performance Monitors (RBPM), which are also called “parrots”, are often associated with ATCBI systems. These systems operate on 1090 MHz and require an assignment. The purpose is to provide a known fixed return to the beacon system for calibration. Mode-S systems usually have two parrots associated with the system. Often these systems are located very close to the ATCBI and require only minimal power.

Assignments to support a parrot should include the delay characteristics in microseconds and nautical miles if a delay line is inserted in the system. The beacon code used and the altitude setting of the parrot should also be in the assignment. Altitude settings must be maintained to either 60,000 feet or above, or below sea level to prevent interference to TCAS.

Page 143 6050.32B Chapter 13 – continued 11/17/05 FIGURE 13-3. RADAR AND ASSOCIATED BEACON CAPABILITIES RADAR PRR CAPABILITIES ASSOCIATED BEACON PRR AN/CPN-4 1500 300 AN/FPN-47 See ASR-5 See ASR-5 AN/FPS-7 244 Same as primary radar AN/FPS-18 1200 300 AN/FPS-20, -20A 350, 355, 360, 365, 370 Same as primary radar AN/FPS-64, -65, 340, 345, 350, 355 Same as primary radar -66, -67 360, 365, 370 AN/GPS-4 360 Same as primary radar AN/GPN-12 See ASR-7 See ASR-7 AN/GPN-20 See ASR-8 See ASR-8 AN/GPN-30 See ASR-11 See ASR-11 AN/MPN-13, -14 1100 275 (4:1 countdown from primary) AN/MPS-11 360 Same as primary radar AN/TPS-43 227, 250, 278 Same as primary radar (3X stagger) AN/TPS-43E 245, 250, 258 Same as primary radar (6X stagger: 245.1, 235.3, 227.3, 278.6, 263.9, 258.4) ARSR-1, -2 See figures 13-5, -6 Same as primary ARSR-3 See figures 13-7, -8 Same as primary ARSR-4 See figure 13-9 Same as primary ASR-4, -5, -6 810, 900, 1125, 1140, 3:1 countdown from primary 155, 1170, 1185 ASR-7 See figures 13-10, -11 See figures 13-10, -11 ASR-8 See figure 13-12 See figure 13-12 ASR-9 See figure 13-14 See figure 13-14 ASR-11 722,788,935,1005 Assign fixed PRR of at least 200 PPS (4X stagger) (PRR is independent from primary.

Assign PRR’s as close to 200 PPS as possible.)

1304. FREQUENCY ASSIGNMENT PROCESS IN THE RADAR FREQUENCY BANDS: The below engineering criteria is the “rule-of-thumb” frequency and distance separation to use when supporting radar systems between 1215-1390 MHz, 2700-3000 MHz, 5600-5650 MHz, 9000-9200 MHz, and 15.7-16.2 GHz: Page 144 11/17/05 Chapter 13 - continued 6050.32B FIGURE 13-4. RADAR FREQUENCY-DISTANCE SEPARATION CRITERIA Distance Required in NMI Frequency Separation in MHz 1 – 2.5 30 2.5 – 5 25 5 – 10 23 10 – 50 20 50 – 100 10 100 –150 5 Over 150 0 a. These are general criteria that were developed years ago based on testing. Since they were developed, there have been many changes in the way radar systems perform. Time has proven, however, that with few exceptions, these criteria work to protect cochannel and adjacent channel radar systems from interference. If a frequency cannot be found using these criteria, forward the requirement to Technical Operations ATC Spectrum Engineering Services and a more in depth analysis will be performed.

b. One source of interference that is sometimes encountered, but protection cannot be granted from, is the propagation affect of ducting. Ducting sometimes affects radar systems that have 600 nmi of separation. There is not enough spectrum to reduce the frequency reuse rate to 600 nmi. If ducting between two systems is a consistent problem, frequency reassignments will be considered.

1305. FREQUENCY ASSIGNMENTS IN THE 1215-1390 MHZ BAND . This band is used by the FAA to support en route radar facilities for air traffic control and assignments must be confined to the 1240-1370 MHz frequency band. This sub-band of the 1215-1390 MHz is allocated for aeronautical radionavigation and, generally speaking, receives better protection from interference. When making assignments in this band, the second harmonic may fall in the 2700-2900 MHz terminal radar band and so must be given consideration. If a frequency is required to support an en route radar facility and cannot be accommodated in the 1240-1370 MHz band, forward the requirement to Technical Operations ATC Spectrum Engineering Services.

a. The band 1240-1370 MHz . The majority of radars in this band are the FAA ARSR-1, -2, -3 and -4 and FPS series. The ARSR-1, -2 and FPS series radars have two channels each which may be assigned frequencies within 5-10 MHz since only one channel transmits at a time. The ARSR-3 is a diplex radar and requires two frequencies substantially separated (about 25 MHz) within the band. The ARSR-4 is a diplex radar which requires two frequencies, but the choice of frequencies are limited to those in the ARSR-4 crystal sets. When one frequency is selected, the second frequency is automatically paired 82.85 MHz away.

(1) The ARSR-1, -2, and FPS series are very high power and long range radars. To the extent the terrain permits, they are sited on a clear, high point of terrain. This, of course, extends their RLOS to other long range radars. In the plains area, this is not as much a problem as in the West or East.

(a) Frequency separation between these radars is usually satisfactory at 5 MHz for 100 nmi and 10 MHz for 50 nmi. See figure 13-4. These long range radars (200 nmi range) are usually not sited closer than about 100 nmi, unless terrain factors require closer siting. In these few cases, it will be necessary to give a wider frequency separation.

Page 145 6050.32B Chapter 13 – continued 11/17/05 (b) Band pass filters may have to be used on some older ARSRs to reduce the emitted spectrum to prevent interference to other nearby radars, or even to the ARSRs associated ATCRBS. Contact Technical Operations ATC Spectrum Engineering Services for details.

(c) ARSR-1/2 staggered PRR's. Figures 13-5 and 13-6 provide the average PRRs and stagger PRTs for the ARSR-1/2 radars. The ARSR-1/2 normally uses the high (noted as "H" in the figure) rate PRR sequences, while the low rate (noted as "L" in the figure) sequences are available as a modification to the ARSR-1/2. Both low and high rates are available for the FPS type radars.

FIGURE 13-5. ARSR-1/2 STAGGERED PRR AND PRT VALUES (HIGH) Num HIGH/ Avg Pulse Repetition Time (PRT) in μ s LOW PRR AVG (Hz) PRT1 PRT2 PRT3 PRT4 PRT5 PRT 00 H 352.61 2647 2836 2761 2609 3327 2836 01 H 354.48 2633 2821 2595 3310 3310 2821 02 H 356.38 2619 2806 2731 2582 3292 2806 03 H 359.29 2605 2791 2716 2568 3275 2791 04 H 360.23 2591 2776 2702 2654 3257 2776 05 H 362.19 2577 2761 2699 2540 3239 2761 06 H 364.17 2563 2746 2673 2526 3222 2746 07 H 366.17 2549 2731 2658 2513 3204 2731 08 H 368.19 2535 2716 2643 2499 3187 2716 09 H 370.23 2521 2701 2629 2485 3169 2701 Page 146 11/17/05 Chapter 13 - continued 6050.32B FIGURE 13-6. ARSR-1/2 STAGGERED PRR AND PRT VALUES (LOW) Num High/ Avg Pulse Repetition Time (PRT) in us Low PRR (Hz) PRT1 PRT2 PRT3 PRT4 PRT5 PRT 00 L 279.88 3115 3939 3207 3481 4123 3573 01 L 281.06 3102 3923 3193 3467 4105 3557 02 L 282.33 3088 3905 3179 3451 4087 3542 03 L 283.53 3075 3889 3165 3437 4069 3527 04 L 284.82 3051 3871 3151 3421 4051 3511 05 L 286.12 3046 3853 3137 3405 4033 3495 06 L 287.36 3034 3837 3123 3391 4015 3480 07 L 288.68 3020 3819 3109 3375 3997 3464 08 L 289.94 3008 3803 3095 3361 3979 3449 09 L 291.29 2993 3785 3081 3345 3961 3433 10 L 292.65 2979 3767 3067 3329 3943 3417 11 L 293.94 2966 3751 3053 3315 3925 3402 12 L 295.33 2952 3733 3039 3299 3907 3386 13 L 296.65 2939 3717 3025 3285 3889 3371 14 L 298.06 2925 3699 3011 3269 3871 3355 15 L 299.49 2911 3681 2997 3253 3853 3339 16 L 300.84 2898 3665 2983 3239 3835 3324 17 L 302.30 2884 3647 2969 3223 3817 3308 18 L 303.67 2871 3631 2955 3209 3799 3293 19 L 305.16 2857 3613 2941 3193 3781 3277 20 L 306.65 2843 3595 2927 3177 3763 3261 21 L 308.07 2830 3579 2913 3163 3745 3246 22 L 309.60 2816 3561 2899 3147 3727 3230 23 L 311.04 2803 3545 2885 3133 3709 3215 24 L 312.60 2789 3527 2871 3117 3691 3199 25 L 314.17 2775 3509 2857 3101 3673 3183 26 L 315.66 2762 3493 2843 3087 3655 3168 27 L 318.78 2735 3459 2815 3057 3619 3136 29 L 320.41 2721 3441 2801 3041 3601 3121 30 L 322.06 2707 3423 2787 3025 3583 3105 31 L 323.62 2694 3407 2773 3011 3565 3090 32 L 325.31 2680 3389 2759 2995 3547 3074 33 L 326.90 2667 3373 2745 2981 3529 3059 34 L 328.62 2653 3355 2731 2965 3511 3043 35 L 330.36 2639 3337 2717 2949 3493 3027 36 L 332.01 2626 3321 2703 2935 3475 3012 37 L 333.78 2612 3303 2689 2919 3457 2996 38 L 335.46 2599 3287 2675 2905 3439 2981 39 L 337.27 2585 3269 2661 2889 3421 2965 40 L 339.10 2571 3251 2647 2873 3403 2949 41 L 340.83 2558 3235 2633 2859 3385 2934 42 L 342.70 2544 3217 2618 2843 3367 2918 43 L 344.47 2531 3201 2605 2829 3349 2903 44 L 346.38 2517 3183 2591 2813 3331 2887 45 L 348.31 2503 3165 2577 2797 3313 2871 46 L 350.14 2489 3149 2563 2783 3295 2856 Page 147 6050.32B Chapter 13 – continued 11/17/05 (2) The ARSR-3 is a simplex radar requiring a pair of frequencies, one for each channel. Although they are time sequenced to operate from different time zeros, the two assigned frequencies should be separated at a minimum of 25 MHz. This could entail shifting other radars in the area to other frequencies in the band.

Technical Operations ATC Spectrum Engineering Services engineers the frequency pairs.

(a) The ARSR-3 associated beacon uses an identical staggered or nonstaggered trigger used by the ARSR-3 itself. Four fixed pulse repetition rates are available from a front panel selection. However, the PRT is expressed in nmi with the basic rate designated as "A." For example: A = 238 nmi = 238 X 12.355 usec = 2,940.5 usec. Note that theoretically it would take a radar signal 12.355 usecs to go out 1 nmi, hit a target and return the 1 nmi. If a value for "A" is chosen between 222 and 261 nmi, the four fixed intervals are selected automatically by the following trigger sequence: A + 16, A, A - 8 and A - 16. For example: A = 238 nmi; the four fixed PRRs would be equivalent to 254, 238, 230 and 222 nmi.

(b) The staggered trigger sequence selected depends on the nmi range selected for "A." There are three stagger sequences available, known as Variable Interpulse Periods (VIP). They are VIP-8, VIP-7, and VIP-5 (see figures 13-7 and 13-8). If "A" is between 235 and 261 nmi, the sequence is VIP-8; if between 228 and 235 nmi, VIP-7; if between 222 and 228 nmi, VIP-5. The VIP number indicates the number of different pulse intervals.

Page 148 11/17/05 Chapter 13 - continued 6050.32B FIGURE 13-7. ARSR-3 PRR CAPABILITIES ARSR-3 OPERATIONAL PRR MODES 1. Stagger trigger (Normal selection) 2. Nonstagger trigger (Special) STAGGER/NONSTAGGER TRIGGER PRR Stagger Trigger PRR (three trigger sequences, determined by value of "A" in nmi) VIP-8 - "A" = any nmi integer between 235 and 261 Sequence: A-32 nmi, A+24 nmi, A-16 nmi, A+8 nmi, A-8 nmi, A+16 nmi, A-24 nmi, A+32 nmi. (eight different PRTs) VIP-7 - "A" = any nmi integer between 228 and 235 Sequence: A-24 nmi, A+24 nmi, A-16 nmi, A+8 nmi, A-8 nmi, A-8 nmi, A±0 nmi, A-24 nmi, A+40 nmi. (nine different PRTs) VIP-5 - "A" = any nmi integer between 222 and 228 Sequence: A-16 nmi, A+8 nmi, A+16 nmi, A+24 nmi, A-16 nmi, A-8 nmi, A-16 nmi, A+40 nmi. (eight different PRTs) Non-stagger PRR (four trigger sequences, determined by value of "A" in nmi) "A" = any nmi integer between 222 and 261 Sequence: A+16 nmi, A ±0 nmi, A-8 nmi, A-16 nmi.

Page 149 6050.32B Chapter 13 – continued 11/17/05 FIGURE 13-8. ARSR-3 AVERAGE VIP PRTS NMI AVG PRT AVG PRR NMI AVG PRT AVG PRR (usec) (pps) (usec) (pps) VIP-8 235 2904.43 344 249 3077.47 325 236 2916.79 343 250 3089.83 324 237 2929.15 341 251 3102.19 322 238 2941.51 340 252 3114.55 321 239 2953.87 339 253 3126.91 320 240 2966.23 337 254 3139.27 319 241 2978.59 336 255 3151.63 317 242 2990.95 334 256 3163.99 316 243 3003.31 333 257 3176.35 315 244 3015.67 332 258 3188.71 314 245 3028.03 330 259 3201.07 312 246 3040.39 329 260 3213.43 311 247 3052.75 328 261 3225.79 310 248 3065.11 326 VIP-7 228 2816.94 355 233 2866.38 349 229 2829.30 353 234 2827.74 347 230 2841.66 352 235 2891.10 346 231 2854.02 350 VIP-5 222 2742.81 365 226 2792.25 358 223 2755.17 363 227 2804.61 357 224 2767.53 361 228 2816.97 355 225 2779.89 360 Page 150 11/17/05 Chapter 13 - continued 6050.32B (3) The ARSR-4 is a diplex radar with two separate frequencies within the band which are paired using the pairing scheme in figure 13-9. Although the ARSR-4 can operate and frequency hop throughout the 1215- 1400 MHz band, day-to-day frequency assignments/operations are confined to two frequencies in the spectrum allocated for aeronautical radio navigation between 1240-1370 MHz.

FIGURE 13-9. ARSR-4 CRYSTAL OSCILLATOR, STABILIZED LOCAL OSCILLATOR (STALO) AND TRANSMIT FREQUENCIES ODD GROUP CRYSTALS (MHz) XTAL OSC. STALO SET 1 SET 2 NO. FREQ. FREQ. LOWER UPPER LOWER HIGHER 01 45.5929 1458.97 1215.58 1298.94 1255.94 1308.79 03 45.7548 1464.15 1220.76 1303.62 1231.12 1313.97 05 46.2402 1479.69 1236.29 1319.15 1246.65 1329.51 07 46.4021 1484.87 1241.47 1324.33 1251.83 1334.69 09 46.8876 1500.40 1257.01 1339.87 1267.37 1350.22 11 47.0494 1505.58 1262.19 1345.04 1272.54 1355.40 13 47.5349 1521.12 1277.72 1360.58 1288.08 1370.94 15 47.6967 1526.29 1282.90 1365.76 1293.26 1376.12 17 48.1822 1541.83 1298.44 1381.29 1308.79 1391.65 19 48.3440 1547.01 1303.62 1386.47 1313.97 1396.83 EVEN GROUP CRYSTALS (MHz) 02 45.6738 1461.56 1218.17 1301.03 1228.53 1311.38 04 45.8357 1466.74 1223.35 1306.21 1233.71 1316.56 06 46.3212 1482.28 1238.88 1321.74 1249.24 1332.10 08 46.4830 1487.46 1244.06 1326.92 1254.42 1337.28 10 49.9685 1502.99 1259.60 1342.46 1269.96 1352.81 12 47.1303 1508.17 1264.78 1347.63 1275.13 1357.99 14 47.6158 1523.71 1280.31 1363.17 1290.67 1373.53 16 47.7776 1528.88 1285.49 1368.35 1295.85 1378.71 18 48.2631 1544.42 1301.03 1383.88 1311.38 1394.24 20 48.4250 1549.60 1306.21 1389.06 1316.56 1399.42 Page 151 6050.32B Chapter 13 – continued 11/17/05 b. The bands 1215-1240 and 1370-1390 MHz . Radars assigned in these bands will be primarily for DOD use. In these cases, the FMO has the same responsibility under NTIA directive to provide just as adequate interference protection to DOD/DOD radars as provided for DOD/FAA adjacent systems. The FMO should work very closely with the appropriate DOD AFC to provide the best separation possible commensurate with good spectrum utilization and conservation.

1306. FREQUENCY ASSIGNMENTS IN THE 2700-3000 MHZ BAND . This band is not exclusive to FAA.

The 2900-3000 MHz portion is used by NWS solely for the NEXRAD weather radar. The FAA is designated by NTIA as the field coordinator for the 2700-2900 MHz portion of the band which is for aeronautical radionavigation services, meteorological aids and the DOD area surveillance radars. Because of this field coordination authority, the FMO selects and recommends frequencies in the 2700-2900 MHz band for all agencies which have a requirement to use this band. Subsequently, the agency, not the FAA, is required to process their frequency request through NTIA for formal assignment with the proper FAA coordination note.

a. FAA 2700-3000 MHz assignments .

(1) In general , if a radar frequency being considered is not within RLOS to any other radar within ±10 MHz, the assignment should be acceptable. Reflections from mountainous terrain could cause interference, so two radars within reflection range should be separated 5 to 10 MHz to prevent problems. Consideration should also be given to the second harmonic of enroute radars operating in the 1240-1370 MHz band. If one of the radars is not crystal controlled, periodic frequency checks should be made of to prevent gradual drift onto the other radar's frequency.

(2) A diplex radar is designed to take advantage of the differences in propagation between two separated frequencies, and thus it is desirable to separate the two frequencies as much as possible.

Page 152 11/17/05 Chapter 13 - continued 6050.32B (a) The ASR-7 is a diplex radar but only on the channels shown in figure 13-10.

FIGURE 13-10. ASR-7E PRIMARY RADAR FREQUENCY PAIRS Channel A (MHz) Channel B (MHz) 2705 2855 2710 2770 2710 2795 2715 2820 2720 2780 2720 2785 2725 2860 2730 2790 2740 2800 2750 2810 2755 2850 2760 2820 2760 2850 2765 2880 2770 2830 2770 2850 2780 2840 2790 2850 2800 2860 2810 2870 2820 2750 2820 2880 2820 2890 2830 2890 2830 2895 Page 153 6050.32B Chapter 13 – continued 11/17/05 (b) The PRR/PRT stagger sequences are shown in Figure 13-11.

FIGURE 13-11. ASR-7 AND ASSOCIATED BEACON STAGGERED PRR AND PRT EQP SET PRR PRT PRR PRT PRR PRT PRR PRT PRR PRT PRR PRT PRR PRT PRR PRT RDR P 1200 833 1173 853 1120 893 1050 953 950 1053 713 1403 --- --- --- --- BCN P 554 1806 530 1886 436 2296 350 2859 447 2236 542 1846 525 1906 320 3129 RDR Q 1188 841 1161 862 1109 902 1039 963 940 1064 706 1417 --- --- --- --- BCN Q 548 1825 525 1905 431 2319 346 2889 443 2258 536 1865 519 1926 316 3160 RDR R 1176 850 1150 870 1098 911 1029 972 931 1074 699 1431 --- --- --- --- BCN R 543 1842 520 1924 427 2342 343 2916 438 2281 531 1883 514 1943 313 3192 RDR S 1164 858 1138 879 1086 920 1019 982 921 1085 692 1445 --- --- --- --- BCN S 537 1861 515 1943 423 2365 339 2946 434 2303 526 1902 509 1964 310 3223 RDR T 1152 866 1126 887 1075 929 1008 991 912 1095 684 1459 --- --- --- --- BCN T 532 1878 510 1961 419 2388 336 2973 430 2325 521 1920 545 1982 307 3254 RDR U 1140 875 1114 896 1064 938 996 1001 902 1106 677 1473 --- --- --- --- BCN U 527 1897 505 1981 415 2411 333 3003 426 2348 516 1939 449 2002 304 3286 Notes: PRR in pps PRT in usec RDR = radar BCN = beacon interrogator Primary ASR-7 is 6X stagger; associated beacon is 8X stagger AVERAGE PRR's Set Bcn Avg Radar Avg P 445 1002 Q 441 992 R 438 982 S 432 973 T 428 964 U 424 954 Page 154 11/17/05 Chapter 13 - continued 6050.32B (c) The ASR-8 dual channel radar presents special problems in providing paired frequencies for it.

The emitted spectrum of the transmitter is about ±10 MHz, about the same as the ASR-7. Associated PRR/PRT stagger sequences are shown in figure 13-12. But the big problem is the receiver band pass. Each receiver is approximately ±40 MHz wide. In addition, there is a manufacturer's limitation that the individual channels must be separated by an amount greater than 60 MHz. See figure 13-13. To fit ASR-8 diplex frequencies into an already congested environment presents the FMO with a very difficult task. Because changing a frequency in an ASR-8 requires replacing a whole transmitter package that includes oscillators and diplexer, a frequency change will be considered only as a last resort for an RFI problem remedy. Any ASR-8 frequency problem should be referred to Technical Operations ATC Spectrum Engineering Services.

FIGURE 13-12. ASR-8 AND ASSOCIATED BEACON STAGGERED PRR AND PRT PRR AVG BEACON PRR RADAR 4X DESIG- RADAR 3:1 CNTDWN STAGGER SEQUENCE NATION PRR PPS / Φ SEC PRT ( Φ SEC) BASIC 1040 347 / 2883 830 1177 876 961 0.5 1035 345 / 2898 835 1182 881 966 1.0 1030 343 / 2913 840 1187 886 971 1.5 1025 342 / 2928 845 1192 891 976 2.0 1020 340 / 2940 849 1197 896 980 2.5 1015 338 / 2958 855 1202 901 986 3.0 1010 337 / 2970 859 1206 905 990 3.5 1005 335 / 2985 864 1211 910 995 4.0 1000 333 / 3000 868 1216 915 1000 4.5 995 332 / 3015 874 1221 920 1005 5.0 991 330 / 3027 878 1225 924 1009 5.5 986 328 / 3042 882 1229 929 1014 6.0 981 327 / 3057 887 1234 934 1019 6.5 977 325 / 3072 892 1239 939 1024 7.0 973 324 / 3084 897 1244 943 1028 Page 155 6050.32B Chapter 13 – continued 11/17/05 FIGURE 13-13. TYPICAL ASR-8 RECEIVER SUSCEPTIBILITY PASS BAND (d) The ASR-9 radar is a single channel/dual frequency terminal radar. Only one channel, manually selectable by the operator, is on the air at any one time. Available crystals allow tuning throughout the band in 1 MHz increments between 2703-2987 MHz. PRR stagger sequences are shown in figure 13-14. While it is possible to have the ASR-9 channels as little as 10 MHz apart, it is advantageous to separate the channels by at least 50 MHz in order to allow frequency diversity to mitigate radio interference and anomalous propagation.

Page 156 11/17/05 Chapter 13 - continued 6050.32B FIGURE 13-14. ASR-9 RADAR AND BEACON PRRS BEACON PRR, NORMAL MODE Staggered PRR (per CPI pair) Average PRR (per CPI pair) BCN RADAR 00 440 440 514 514 342 514 330 429 1172 01 434 434 506 506 338 506 326 423 1156 02 434 434 506 506 338 506 326 423 1156 03 431 431 503 503 335 503 323 420 1148 04 428 428 499 499 333 499 321 417 1140 05 425 425 496 496 331 496 319 414 1132 06 422 422 493 493 328 493 317 411 1124 07 419 419 489 489 326 489 315 408 1116 08 417 417 486 486 324 486 312 406 1109 09 414 414 483 483 322 483 310 403 1101 10 411 411 479 479 320 479 308 400 1094 11 408 408 476 476 318 476 306 397 1087 12 406 406 473 473 315 473 304 395 1080 13 403 403 470 470 313 470 302 392 1073 14 400 400 467 467 311 467 300 390 1066 15 398 398 464 464 309 464 298 387 1059 BEACON PRR, VIP MODE Staggered PRR, (per CPI pair) Average PRR, (per CPI pair ) 16 436 433 513 512 340 511 329 426 1164 17 433 430 510 508 337 507 327 423 1156 18 430 427 506 505 335 504 325 420 1147 19 427 424 503 501 333 500 322 417 1140 20 424 421 499 498 330 497 320 414 1131 21 421 419 494 496 328 493 318 411 1124 22 418 416 492 491 326 490 316 408 1116 23 415 413 489 487 324 487 314 406 1108 24 413 410 486 484 322 483 312 403 1101 25 410 407 482 481 319 480 309 400 1094 26 407 405 479 478 317 477 307 398 1087 27 404 402 476 475 315 474 305 395 1080 28 402 400 473 471 313 471 303 392 1072 (e) The ASR-11 radar is a diplex radar that requires two frequency pairs for operation. The two frequency pairs may be selected from anywhere within the 2702.6 – 2897.5 MHz tuning range, but must be separated by at least 30 MHz. Each pair consists of two frequencies that are +/- 0.5 MHz offset from the main carrier. The carrier frequency is what is assigned so each ASR-11 will only have two frequency assignments even though it operates on four frequencies. An assignment of 2730 MHz, for example, with result in actual operations being on 2729.5 MHz and 2730.5 MHz, but only an assignment on 2730 MHz is needed. The second assigned frequency in this example must be at least 30 MHz from 2730 MHz. This assignment process is permitted by NTIA because of the EMC emission level provisions and the purity of the transmissions. The ASR-11 uses a four times stagger that is not adjustable. The average PRF for all ASR-11s is 856 PPS. The associated monopulse Page 157 6050.32B Chapter 13 – continued 11/17/05 beacon system is independent of the ASR-11 and accepts a fixed PRF assignment between 200 and 450 PPS.

Due to the increased accuracy that is realized by a monopulse beacon, however, PRR assignments will be as close to 200 PPS as possible to reduce the amount of FRUIT produced by 1030 MHz interrogations.

b. Non-FAA 2700-2900 MHz assignments .

(1) NWS Radars . Some of the older style weather radars operated by the NWS such as WSR-57 and WSR-74 still operate in this band. They are tunable but have rather poor spectra. Generally speaking, separation from FAA ASR series, except ASR-8, needs to be about 20 MHz within RLOS. In the case of the ASR-8, a clear band ±40 MHz for each channel frequency is required. Because of the relatively unstable operating parameters of those older radars, they need to be checked on a case-by-case basis. Joint DOD/FAA/NWS NEXRAD, also known as WSR-88D, is replacing the entire NWS inventory. NEXRAD installations must be coordinated carefully between FAA/NWS, particularly, the site locations.

(2) DOD Radars . Most of the DOD permanent requirements in this band will be for radars that are the DOD equivalents of FAA radars, such as the AN/GPN12 (ASR-7), AN/GPN20/GPN27 (ASR-8), and AN/GPN- 30 (ASR-11). Assuming these are in ATC use around military bases, the FMO shall give the same protection and availability as FAA and NWS radars. Should the request be for tactical or training purposes, that function is secondary to all others and may be accommodated only if there is space without crowding or moving any of the ATC or NWS radars.

(3) Non-FAA/non-NWS/non-DOD Radars . This group will consist primarily of non-federal radars and usually will be experimental systems to develop air traffic control radar, tactical systems, or radar systems for foreign sale. These requirements will be secondary and handled on a case-by-case basis, in coordination with Technical Operations ATC Spectrum Engineering Services.

1307 . FREQUENCY ASSIGNMENTS IN THE 5600-5650 MHZ BAND . TDWR presently is the only radar that FAA operates in this band. The band is shared with various weather radars operated by the DOD, NWS, and commercial weather radar systems usually associated with local new television stations. TDWRs are normally sited off the airport in order to provide better surveillance in the area of that airport. Therefore, in some cases, TDWRs are located adjacent to public facilities, and FMOs need to take special care that pre-commissioning radiation measurements are known and documented. When engineering an operating frequency for the TDWR, a circle search using the GMF and taking into account assigned frequencies as low as 5.4 GHz must be made in order to ensure compatibility with existing radars in the band 5.600-5.650 GHz as well as wide band radars operated by other agencies in the spectrum below 5.6 GHz. In addition, when siting TDWRs, in the vicinity of ASRs, the second harmonic relationship between 2.700-2.900 GHz band and the 5.600-5.650 GHz band must be considered.

1308 . FREQUENCY ASSIGNMENTS IN THE 9000-9200 MHZ BAND. FAA operates the ASDE-X radar system in this band. Although the ASDE-X system can operate on up to four frequencies in the band, minimum performance standards can be met on two frequencies. The band is also used by the military for Precision Approach Radar (PAR). When making assignments for an ASDE-X system, a distance of 18 nmi between the ASDE-X and PAR is usually sufficient. If the proposed separation between systems is less then 18 nmi, then forward the requirement to Technical Operations ATC Spectrum Engineering Services for a more in-depth analysis. For PAR and other military operations in this band, the FMO engineers and recommends a frequency for the DOD requestor, just as with the other bands in this chapter. However, since the FMO normally is not familiar with these DOD radars, it is best to coordinate with the appropriate DOD AFC and use the DOD's expertise in this area as FAA's recommendation. Should any user of this band contact the FMO reporting interference, the FMO shall take the lead in resolution of the problem as the NTIA designated field coordinator for this band.

Page 158 11/17/05 Chapter 13 - continued 6050.32B 1309 . FREQUENCY ASSIGNMENTS IN THE 15.7-16.2 GHZ BAND . This band is used by FAA for ASDE-3 but is shared with and subject to coordination with DOD as coequal. Non-Federal users are permitted in this band on a noninterference basis to ASDE-3. For all ASDE-3 frequency assignments, the FMO shall coordinate with Technical Operations ATC Spectrum Engineering Services.

1310. thru 1399. RESERVED .

Page 159 (thru 166)

11/17/05 6050.32B CHAPTER 14. RADIO FREQUENCY INTERFERENCE 1400. INTERFERENCE PROBLEMS . Effective reporting and timely awareness of a Radio Frequency Interference (RFI) problem is essential before a resolution approach can take place. To resolve RFI, the Frequency Management Officer (FMO) must be resourceful and have a wealth of analytical experience and good technical references. This chapter is a good reference and it outlines the general procedures to follow in the resolution of RFI to National Airspace System (NAS) services. For all reported events of RFI it is critical that the service area FMO do a thorough desktop analysis of the situation to determine the approach to a potential solution and the resources that will be required. An additional reference guide for applying radio interference investigation techniques is the Radio Frequency Interference (RFI) Detection, Analysis and Resolution textbook, prepared for Technical Operations ATC Spectrum Engineering Services. This pamphlet is supplied to Technical Operations Services specialists and service area FMOs during the Radio Frequency Interference Resolution training course (Course # 45018) and further copies are available upon request.

1401. INTERFERENCE REPORTING . Whether the RFI problem is resolved locally or not, the RFI event must be reported to Technical Operations ATC Spectrum Engineering Services. On a regular basis, Technical Operations ATC Spectrum Engineering Services receives inquiries, congressional and otherwise, concerning ongoing interference problems affecting NAS services. Headquarters must be in a position to promptly reply on the status of any problem at any time. Order 6050.22C prescribes policies and procedures for reporting and investigating intentional interference (phantom controllers incidents). The following general guidelines shall be used for RFI reporting: a. Use of the Maintenance Management System (MMS): System Management Office (SMO) or Systems Operations Center (SOC) specialists are required to perform MMS log entries. FAA Form 6050-3, Frequency Interference Report is no longer required.

b. Facility service event associated with the RFI: The National Airspace Performance Reporting System (NAPRS) Interrupt Report (LIR) or Administrative Report (LAD) log entry shall be used.

c. Facility service interruption associated with the RFI: The NAPRS LIR Line/Frequency (LLF) log entry shall be used. For NO service interruption the LAD log entry shall be used.

d. For the LIR/LLF and LAD: (1) Enter 84 in the CODE CAT field (LIR/LLF). Enter 07 in the CODE CAT field (LAD) (2) Enter the duration of the RFI in the OPEN/START and ENTRY/CLOSE fields.

(3) Enter the affected frequencies and channels in the appropriate data fields.

(4) Enter a brief description of the interference and information regarding any actions started or completed in the COMMENTS field. Additional comments may be added by supporting organizations, e.g., SMO, service area FMO, etc.

e. Separate logs: If required, separate or associated logs should be created for each RFI incident and linked to the parent log via the RELATED LOG ID field referencing the record or log ID number of the parent log.

f. MMS Report format: This information is available in detail in FAA Order 6000.48, General Maintenance Handbook for Automated Logging.

g. Use of the Spectrum Management Data Base (SMDb): Radio Frequency Interference events not logged in the MMS system by SMO or SOC field specialists must be logged in the National Airspace System (NAS) RFI or Global Positioning System (GPS) RFI modules of the SMDb system. The SMDb is available over the FAA intranet secured network at http://asr.faa.gov/. Authorized users navigate via the FAA intranet to the Technical Page 167 6050.32B Chapter 14 - continued 11/17/05 Operations ATC Spectrum Engineering Services website link, the SMDb NAS RFI and GPS RFI reporting tools become available. A system User Identification (USER ID) and password is required for access to these secured areas of the database. No USER ID is required to access the online HELP link, which provides the SMDb System User Manual for detailed instructions on how to create and record a particular RFI event.

h. Service Area FMO upward reporting . The nature and particularly the impact and importance of an RFI problem must be carefully weighed. If there is a reasonable chance that the RFI might be of immediate interest to headquarters, Technical Operations ATC Spectrum Engineering Services shall be advised immediately. The following types of RFI incidents require the Technical Operations ATC Spectrum Engineering Services liaison at the FAA National Operations Control Center (NOCC) in Herndon, VA, to be contacted with the following information: (1) Problems with equipment design or design deficiency.

(2) Problems dealing with major or hub airports.

(3) Problems indicating FAA and FCC/NTIA frequency standards are in conflict.

(4) Any interference receiving media attention.

(5) Any interference connected with an accident or incident.

(6) Any interference , which might arouse political or aviation community interest.

(7) Any interference causing a facility to be shut down or restricted.

(8) Any interference to high frequency (HF) assignments.

(9) Any interference attributable to testing, either by another entity or through FAA procedures ( e.g., maintenance or others ) .

1402. ADMINISTRATIVE PROCEDURES . Determining the source or cause of interference to NAS services determines the administrative procedures required for quick resolution.

a. Unknown source: An in-depth desk analysis is the first step in determining the source of RFI. RFI sources begin as an unknown source until positive correlation can be made with a commercial, civil government or military establishment. While reports are being obtained, the FMO shall use any available automation analysis tools to reduce the area from where a culprit source may be radiating the RFI. Technical Operations ATC Spectrum Engineering Services makes available the Radio Coverage Analysis System (RCAS), Airspace Analysis Model (AAM), Space Loss Calculator (SLC), and Aircraft Situation Display (ASD) automation tools. These tools combined with effective reporting data bases will assist in narrowing the potential geographical location of the RFI source and provide valuable information for a possible airborne mission. In addition, the FMO shall contact the Technical Operations ATC Spectrum Engineering Services liaison at the NOCC for additional expertise in conducting the desk analysis. The Technical Operations ATC Spectrum Engineering Services Liaison may establish teleconferences with concerned air traffic organization personnel to obtain additional RFI reports from facilities or pilots.

b. Non-Government source: The Federal Communications Commission (FCC) is the government agency that has regulatory oversight on non-government sources. The appropriate local FCC Field Office shall be contacted by the FAA service area FMO for proper coordination. When a private proponent has been determined as the source, careful judgment must be exercised in approaching the owner of the establishment or equipment.

The FCC should be contacted first for awareness and coordination. The FCC may exercise administrative or other legal procedures depending on their history records on the proponent. In addition, the Technical Operations ATC Spectrum Engineering Services liaison to the NOCC shall be contacted in the event that the FCC national Page 168 11/17/05 Chapter 14 - continued 6050.32B Communications Crises Control Center (CCCC) support is necessary. For situations regarding intentional interference the guidelines in Order 6050.22 shall be followed.

c. Government source: RFI incidents caused by another government organization shall be resolved and coordinated locally to the extent possible with the government agency's technical representative responsible for the operation of the offending equipment. If unsuccessful notify the Technical Operations ATC Spectrum Engineering Services liaison at the NOCC with all necessary details related to the identified RFI problem and let the national liaison coordinate resolution at the FAA headquarters level. Service area FMO personnel are encouraged to participate in local state government frequency management meetings and forums to establish good working agreements.

d. Airborne RFI investigation support: The service area FMO will be the focal point authorized to make requests for airborne RFI investigation support. The FMO shall coordinate the airborne RFI investigation through the national Technical Operations ATC Spectrum Engineering Services liaison at the NOCC. A simple electronic mail message describing the nature of the pilots-only reported RFI should be sent by service area FMOs to the Technical Operations ATC Spectrum Engineering Services NOCC liaison to quickly initiate the coordination process. The electronic mail request shall be followed with a formal memo to the Directors of Technical Operations ATC Spectrum Engineering Services and Technical Operations Aviation System Standards.

The Technical Operations ATC Spectrum Engineering Services intranet website also has an electronic airborne support request form that will allow the service area FMO to initiate coordination for scheduling an aircraft from any location where he/she has access to the FAA network. This tool may be used as an alternative to electronic mail for requesting airborne RFI investigation support.

(1) Technical Operations ATC Spectrum Engineering Services NOCC Liaison: The specialist at this office will gather all pertinent RFI problem data from the service area FMO, SOC, SMO, or concerned air traffic organization facility. After sufficient data to initiate an RFI investigation flight pattern is obtained, coordination with the Flight Inspection Central Operations (FICO) office is performed via telephone. The FICO will determine the earliest dates, crews and aircraft that will support the airborne RFI mission. This telephone request will be followed up by electronic message with any further details that will aid the flight crew in performing the airborne search.

(2) Non-FAA aircraft: Airborne RFI investigations for the restoration of NAS navigation, communication or surveillance services can only be performed under an approved FAA flight program. The Navigational Aids Signal Evaluator Radio Frequency Interference (NASE/RFI) is the Technical Operations Aviation Systems Standards primary approved flight program for airborne RFI investigations. The FAA research and development flight program managed by the William J. Hughes Technical Center is the second alternative.

RFI airborne investigations outside an FAA approved flight program require special exceptions and approval from Technical Operations ATC Spectrum Engineering Services. Technical Operations ATC Spectrum Engineering Services may specifically authorize the Ohio University Avionics Engineering Center flight program to execute an airborne RFI investigation when none of the FAA flight program aircraft are available.

e. Costs Expenditures: In all RFI investigation cases, accurate records should be kept on the costs and funds expended to investigate the RFI event including man-hours and when applicable, aircraft hourly rate costs.

These costs shall be logged in the SMDb costs entry fields.

f. RFI Suppression Devices: These types of devices are implemented when frequency management engineering criteria for equipment electromagnetic compatibility at FAA facilities is difficult to attain. These conditions exist when a transmitter is in close physical proximity or in close frequency proximity to a victim receiver. The following FAA policy addresses the use of RFI suppression devices such as multicouplers, combiners, isolators, etc. to resolve cosite problems: (1) Technical Operations ATC Spectrum Engineering Services will manage the overall program for requirements and budgetary purposes.

Page 169 6050.32B Chapter 14 - continued 11/17/05 (2) FMOs shall validate the requirements for multicoupler and combiners within their service area in coordination with the Regional Associate Program Managers (RAPM).

(3) FMOs must carefully specify requirements for combiners. Combiners have a very narrow range of operating frequencies. Multicouplers are flexible in their potential for retuning to meet changing requirements.

(4) FMOs shall note the use of multicouplers or combiners in the GMF remarks section using the appropriate format.

1403. INTERNAL PROCEDURES . RFI resolution techniques may vary from service area to service area, depending on the service area organizational structure, policies and the FMO's available RFI mitigation assets.

The following procedures are recommended as general guidelines that may be adjusted to meet specific service area needs: a. SMO frequency coordinators : Identify focal points and agreements at the SMO level. Technical Systems Offices (TSO) personnel at the SMO level have been designated as RFI focal points and are good resources.

b. SMO interference liaisons: Designate key service area air traffic organization and Technical Operations Services management personnel to coordinate regular meetings and to assure Air Traffic personnel reports any interference to the SMO frequency coordinators focal point promptly.

c. Service area air traffic organization/Technical Operations Services Outreach: Establish periodic teleconferences or briefings with service area air traffic organization and Technical Operations Services branches within the service area offices toward increasing RFI impact awareness. The Technical Operations ATC Spectrum Engineering Services liaison at the NOCC provides a daily status of RFI events being tracked in the NAS during the morning national operations teleconference. FMO and SMO participation on this national teleconference is highly encouraged.

d. Prompt Notification: Establish a chain of contacts at the SMO and FMO, when an RFI problem has been found to be a defective FAA transmitter. The SMO shall request FMO assistance in certifying the RFI cause.

Confirming ON/OFF tests shall be performed; remedial filter recommendations, suggestions and engineering observations using FMO interference locating and measuring equipment shall be completed.

e. Seamless Service Area Support: During difficult and critical RFI events requiring additional resources or when FMO personnel shortages impact the service area’s ability to resolve RFI, a request for "Seamless Service Area Support" shall be coordinated. The FMO is the focal point to coordinate "Seamless Support." RFI events impacting NAS services shall be given the highest priority and support coordinated with the Technical Operations ATC Spectrum Engineering Services liaison office at the NOCC. The Technical Operations ATC Spectrum Engineering Services management staff will give final "Seamless Support" approval.

1404. INTERFERENCE LOCATING EQUIPMENT . Service area FMOs have several types of direction finding equipment utilizing proven signal monitoring technologies. The equipment is used to assist the FMO’s skills to resolve RFI. The FAA Radio Frequency Interference (RFI) Detection, Analysis and Resolution textbook is a detailed reference source of information on equipment and techniques. Basic general guidelines for resources and equipment are as follows: a. Telephone Lists : Comprehensive lists of contacts are important namely; FCC, other Federal Agencies, other State Agencies, DOD Area Frequency Coordinator (DOD AFC), and private frequency management organizations. Calls to these contacts with a description of the nature of interference assists in the resolution.

Page 170 11/17/05 Chapter 14 - continued 6050.32B b. Audio Recording: RFI audible characteristic is very important in identifying interference sources. The sound of the RFI may provide clues to the source identity. Careful listening to the signal or reviewing audio recordings from air traffic facilities can reveal such things as: (1) Service: Police, Taxi Dispatch, Amateur Radio, Paging, Cellular, etc.

(2) Emission: Pulse modulation (i.e., radar and other pulse type emissions are recognizable by their characteristic "buzz."), Phase Modulation, Frequency Modulation, etc.

(3) Nature: Drifting signals, frequency sweep (i.e., industrial heating device), video field change (i.e., characteristic "hum" change), rhythmic ticking (i.e., timing circuits) musical sound (i.e., varying telemetry signal), etc.

c. Spectrum Analyzer: The spectrum analyzer (SA) is an instrument that should be used by properly trained Technical Operations Services specialists. Short duration or "burst" type signals, complex waveforms signals, and signals that drift within a wideband spectrum are some of the measurement benefits the SA provides to the Technical Operations Services specialists. Locating intermittent RFI is particularly time consuming and use of the SA may provide the necessary clues for RFI resolution.

(1) Overload Caution: The SA has a wideband front end. When high-level signals are present at the RF front end it can generate internal spurious signals, which may appear as if they were real signals. In addition, false signal levels are displayed due to front end overloading condition. The standard procedure to avoid this problem should always be to use a tunable filter or in-line attenuation pads with the SA. In line attenuator pads or filters may reduce the overall sensitivity of the SA, but will permit on-frequency use while rejecting strong off- frequency sources.

(2) No Filter Procedure: The following procedure may prevent the SA overload condition in the presence of high-level signals. Set the SA to monitor the RF signal of interest and note any adjacent signal levels. Insert 10 dB of external attenuation. If all signals presented on the screen are reduced by 10 dB, then the front end is not being overloaded (Note: make sure a wide enough spectrum bandwidth is being measured). If some shown signals drop more than 10 dB, then the front end is being overloaded, and another 10 dB attenuation is required.

When a level of additional insertion occurs where every signal drops equally, the integrity of the front end of the SA is assured. (Note: Attenuation reduces the sensitivity of the SA).

d. Receiver: This type of equipment provides the highest flexibility for investigating RFI in the NAS. Field strength meter receivers are manufactured with great shielding and bonding for great sensitivity and selectivity.

These are costly units and used for specialty applications. Inexpensive general purpose portable receivers may be sufficient for some RFI investigations. In addition, 360, 720 or 760 channel VHF aeronautical transceivers can be reasonably effective in the VHF spectrum under some power line RFI investigations. For best results during RFI investigations, it is recommended that a receiver be used that permits the use of an external antenna, has RF gain control, is shielded, and has a carrier level meter.

e. Antennas: Specific types of antennas connected to a receiver for direction-finding (DF) work will provide the Technical Operations Services specialist with a better probability to quickly locate the RFI source. A Loop, Yagi, Log Periodic, or even a simple Dipole, which can be used for DF, will work appropriately if used according to direction finding techniques. Further details are provided in paragraph 1406 b.

Page 171 6050.32B Chapter 14 - continued 11/17/05 f. Direction Finders: There are DFs configured for fixed remote site operation and those configured for portable mobile operation. The fixed DF configuration is automated and is available for local or remote operation 24 hours and 7 days a week. Portable DFs are available in manual and automated modes. These are used from a fixed location or while in motion.

(1) Fixed DF: Fixed DF facilities are presently limited to high-traffic density areas where RFI has the potential to severely impact NAS services, causing delays and safety risks. They are strategically located to attain triangulation within a geographical area that is within Radio Line of Sight (RLOS) to each of the fixed DF sites.

The expansion of fixed DF sites is expected throughout the NAS in the near future.

(2) Portable DF: Service area FMOs are the focal point that coordinate the use of portable DFs which can be used in a vehicle while in motion in the manual or automated mode. Technical Operations ATC Spectrum Engineering Services also manages a national handheld and portable direction finder program, which utilizes general purpose receivers and processors specially designed for RFI investigation work. Service area FMOs are also the focal point for coordinating the use of these nationally available portable and handheld DF systems with the Technical Operations ATC Spectrum Engineering Services liaison office at the NOCC.

g. RFIM Van: Some RFI events require the use of a vehicle as an efficient tool when used by a proficient operator, especially if the RFI source is suspected to be at some distance from the victim equipment. The ability to take bearings quickly in an automated mode, while traveling, assists in rapid DF triangulation that leads to source location. Service area FMOs are the focal point for coordinating the use of the RFIM van. Further information concerning RFIM vans will be found in Chapter 15.

1405. INTERFERENCE LOCATING TECHNIQUES . The techniques for locating an RFI source vary, depending on the nature of the RFI and the personnel seeking resolution. A rule of thumb is that no condition is to be assumed. All possibilities must be considered. Engineers in the radio frequency field have developed some basic techniques over the years. The following paragraphs provide general guidance, listed by the type of system receiving interference.

a. Ground Communications interference: This is RFI to FAA equipment use for Air/Ground voice communications in the terminal and en route environments. This equipment experiences the most RFI, which can be classified into three basic types: internal, local, and external.

(1) Internal interference is RFI generated within the receiver, normally harmonic or spurious emissions generated by internal crystal oscillators or synthesizers used in the superheterodyne circuitry. This RFI manifests as unmodulated carriers on specific frequencies, appearing constantly. FMOs should examine this possibility prior to seeking for external sources. Aging crystals, oscillator tuning, and change on receiver voltage during routine maintenance can initiate a spurious signal. It is recommended that the antenna be removed from the receiver and the input terminal be grounded. If the signal remains, the source is internal and the receiver should be repaired.

(2) Local interference is RFI caused by other signal sources in the same rack, same room, or same building. Signals generated by another transmitter or receiver can cause a receiver response on the assigned frequency. Service area FMOs should carefully assess, when receiving a complaint, if the interference "just" started. It could have been present since installation of the victim receiver or the source transmitter or receiver, but only recently became noticeable. The problem may be masked by normal squelch setting and then become noticeable only when the squelch level is lowered or increased traffic on the frequency causes the squelch to be opened more frequently.

Page 172 11/17/05 Chapter 14 - continued 6050.32B (a) Intermods: The potential for intermodulation when engineering the frequencies for a site shall be avoided. Lower order (third or fifth order) intermods may exist below squelch until frequent use of the site frequencies unveils its presence. Intermod is easily recognized by its makeup of a mix of two or more facility frequencies other than the victim frequency. Intermods are covered in Appendices 1 and 2.

(b) Some Resolutions : 1 . Antenna relocation (vertical or horizontal separation).

2 . Receiver or transmitter relocation (to another site).

3 . Cavity or crystal filter installation (victim receiver input).

4 . Cavity and/or ferrite isolator installation (transmitter outputs).

5 . Frequency change (last alternative - may introduce new problems).

(3) External interference is RFI caused by a myriad of sources, including such devices as heater thermostats, broken power pole insulators, doorbell transformers, computers, industrial devices using RF energy (i.e., “plastic welders") and almost any conceivable RF source. The problems divide into six major categories: co- channel, adjacent channel, brute force, intermod, image and audio rectification.

(a) Cochannel interference is RFI generated when a signal is within the receiver band pass of the assigned frequency. The victim receiver receives a signal at its detector that is processed as a desired signal. The FMO shall carefully identify the signal (voice, pulse, etc). Careful listening of the interference directly or from AT tapes, shall be performed.

(b) Adjacent Channel interference is RFI caused by signals much broader and stronger than those in the cochannel case. The receiver band pass is a product of its RF and IF band pass circuits, but they are limited in their curve shape due to the Automatic Gain Control (AGC) function of the receiver. Sometimes the channel assigned above or below the victim frequency causes the problem.

(c) Brute Force interference, also known as front-end overload is an exceedingly strong signal which might be anywhere in the radio spectrum. For example, a 50 kilowatt FM broadcast transmitter in the 88 to 108 MHz band a few hundred feet from an FAA receiver can completely overload the receiver. The result is desensitization of the receiver and usually the passing of the FM signal through the receiver. Brute force can also be in-band and near-frequency (i.e., a receiver tuned to 125.575 MHz could be overloaded by a transmitter on 125.60 MHz in the vicinity, assuming its antenna were in proximity). Relocating the transmitter or receiver antenna to achieve 1,000 feet or more separation can cure brute force problems. Installation of a cavity or crystal filter is a good solution as well.

Note: This type of problem normally occurs within the same building, or nearby buildings. To minimize brute force (overload) potential, the FAA cosite standard for frequency separation is 0.5 MHz for VHF (118-137 MHz) and 1.0 MHz for UHF (225-400 MHz) for transmitter and receiver antennas within 80 feet of each other.

(d) Intermodulation (IM) interference normally occurs in a receiver, caused by a combination of external strong signals (2 or more) which algebraically mix to produce the victim frequency, usually in the first mixer or first amplifier. The receiver responds to the mixed frequency as if it were an "on frequency" signal.

Intermods may also occasionally be created within transmitters where they are in close proximity. A spectrum analyzer could be of valuable assistance in determining the interfering signal level.

Page 173 6050.32B Chapter 14 - continued 11/17/05 1 . IM definition: IM is expressed with formulas where the mathematical relationship of various frequencies results in the operating frequency of to the victim equipment. For example: nd 2 Harmonic IM = 2F ; (F = Center Frequency) c c 2 x (121.5 MHz) = 243.0 MHz rd 3 Harmonic IM = 3F ; (F = Center Frequency) c c 3 x (121.5 MHz) = 364.5 MHz Sum/Difference 2 Frequency Third Order IM = 2F ± F 1 2 2 x (119.8 MHz) - 118.1 MHz = 121.5 MHz 2 x (119.8 MHz) + 118.1 MHz = 357.7 MHz Sum/Difference 3 Frequency Third Order IM = F + F ± F 1 2 3 118.1 + 124.7 + 121.3 = 364.1 MHz 118.1 + 124.7 - 121.3 = 121.5 MHz 2 . Receiver IM Resolution: One potential solution is to install a band-reject (notch) filter at the input of the victim receiver, tuned to one of the undesired frequencies that generates the IM inside the receiver.

This reduces one of the undesired signals below the level at which it drives the victim receiver front end into non- linear operation. A second potential solution would be to use a bandpass filter at the victim receiver, tuned to the victim frequency. This is effective, however, only if the culprit frequencies which cause the intermod, are well removed from the victim frequency. The frequency separation requirement is a function of the bandpass filter selectivity curve.

3 . Transmitter IM Resolution: Potential solutions are to use bandpass or band-reject filters at the antenna input of the culprit transmitter. Proximity of strong signal causes unwanted mixing in the amplifier or mixer stage of the transmitter. The transmitter final amplifier is driven by these external signals into non-linear operation, generating and radiating the undesired IM (or spurious) signal on the victim frequency. Since a transmitter is actually radiating the IM (or spurious) signal, nothing can be done at the receiver to resolve the problem, only stopping the undesired strong signals from entering the culprit transmitter yields resolution.

(e) Image interference: This is caused by a strong external signal which mixes with the local oscillator (LO) in the victim receiver to produce the intermediate frequency (IF) which then is processed by the receiver just as if it were a desired "on frequency" signal.

1 . Case example: A Flight Service Station (FSS) receiver is tuned to 121.5 MHz. Its Local Oscillator (LO) is 20.6 MHz above the desired frequency (i.e., 121.5 + 20.6 = 142.1 MHz). If a sufficiently strong signal appears at the victim receiver input from a culprit frequency of 162.7 MHz, this signal will get through the first amplifier of the receiver and mix with the 142.1 MHz LO to produce the intermediate frequency (IF) of 20.6 MHz. See figure 14-1 for a graphical illustration. For aviation frequencies, an LO on the low side (i.e., 121.5 – 20.6 = 100.9 MHz) is avoided because the "image" frequency would be 80.3 MHz, close to TV channel 5 video carrier.

Page 174 11/17/05 Chapter 14 - continued 6050.32B FIGURE 14-1. IMAGE FREQUENCY RELATIONSHIPS 2 . FAA A/G Radios: The commonly used VHF/UHF receivers are the ITT GRR-23, GRR-24 and the Motorola CM200V/U units. The GRR LO's are 20.6 MHz above the desired frequency, except for 322 MHz and higher, where they are below. All CM200 series LO's are 45.0 MHz above the desired receive frequency.

The CM200 also has a second IF at 456 kHz.

3 . Image RFI Resolution is to filter out the undesired signal from entering the victim receiver by reducing its level below that to which the receiver will respond. The amount of rejection required will depend on the filter selectivity curve. Other alternatives are to lower the power of the culprit transmitter, install a directional antenna to discriminates against the victim-culprit azimuth or to move one of the sites further away.

(f) Audio Rectification is interference whereby an audio amplifier is driven into detection mode by the strength of the culprit signal, usually a nearby high power AM broadcast station. At some strength level, any signal can cause a contact (i.e., a transistor input junction, a poor ground connection, etc.) to act as a diode and rectify the signal, then reradiate the detected signal. The signal may be distorted because it is the increase in intensity from the amplitude modulation that drives the device into detection mode. In these cases, an amplifier may act as a radio receiver. The problem usually is at the input stage where the amplification is the greatest and the rest of the amplifiers merely amplify it.

1 . Resolution: One potential solution is to bypass the input circuit with a small (0.005 Microfarad) capacitor between the circuit board ground and the closest possible point of input to the amplifier stage, with the shortest possible leads. Also useful is a ferrite bead on the input line wire. If the strong signal is entering the amplifier cabinet by the power line or remote speaker lines, it is recommended to wrap the line through a ferrite ring, which will act as a radio frequency choke. Sometimes merely plugging in the power cord to another outlet circuit will change the level enough to eliminate the rectification. Each case may be unique, however applying these techniques in a logically progressive manner may yield the solution.

Page 175 6050.32B Chapter 14 - continued 11/17/05 b. Airborne Communications interference is RFI to aircraft receivers which can be difficult to investigate and locate. Because of RLOS, the RFI source affecting a flying aircraft may be located a hundred miles or more from the area where aircraft are being affected. The following procedure is recommended for investigation and location of such RFI sources.

(1) Obtain the following data from the service area air traffic facility: (a) Date and time the RFI reports started (b) Aircraft Location (altitude, latitude, longitude, airline, aircraft type) (c) RFI Occurrence (constant, intermittent, morning, night, weekends) (d) RFI Description (music, voice, squelch breaks, tones) (2) Constant RFI: If the RFI is fairly constant but only one airline reports the problem, suspect their equipment and contact their maintenance department with the information you have obtained from the service area air traffic facility. If several airlines and private pilots have reported the problem then the following is recommended: (a) RFI reports data: Coordinate with the service area air traffic facility to request reports from aircraft at various altitudes in the affected area to monitor the frequency for RFI (targets of opportunity).

(b) RFI data analysis: Analyze the data provided by the service area air traffic facility and plot on a high or low aeronautical sectional map the extreme points at which multiple RFI reports have been received.

(c) Area Reduction: To the extent possible, use the RLOS generated by each aircraft data point and the Venn diagram techniques to identify an area of less than 50 nmi radius having the majority of RFI complaints.

Conduct the following checklist in an attempt to reduce the size of the geographical area to be searched on the ground: 1 . Altitude – reports 6,000 ft below local ground level 2 . Area – 50 nmi east, west, north to south radials centered on the RFI area 3 . AGC level – note on a chart the points where the signal is the strongest 4 . Triangulation – estimate a grid where the source may be located 5 . Repeat steps 1, 2,3 and 4 above – with reports at 2000 ft, 3000 ft, etc.

6 . Reduce area – 20 nmi east-west, north-south. Fine tune estimated area 7 . Proceed with the ground search of the area identified in 4 and 6 above.

(3) Intermittent RFI: If the RFI is intermittent the problem becomes a greater challenge and may require further assistance at the national level. If several airlines and private pilots have reported the problem, the following is recommended: (a) Procedures: The same techniques described under Constant RFI above are applicable when intermittent RFI is reported. Coordination for an FAA flight check is the same as for Constant RFI. However, the Technical Operations ATC Spectrum Engineering Services liaison at the NOCC may coordinate collaborative Page 176 11/17/05 Chapter 14 - continued 6050.32B assistance for additional PIREPS reports from a special RFI working group of the Air Lines Pilots Association (ALPA) named "aeroRFI." Additional assistance may be coordinated with the Air Transport Association (ATA), the National Business Aircraft Association (NBAA), and the Aircraft Owners and Pilots Association (AOPA).

These organizations can provide VHF A/G data link message reports to the Technical Operations ATC Spectrum Engineering Services NOCC liaison for further analyzing the geographical area of the RFI.

c. NAVAID interference: This type of RFI is more difficult to identify and is generally first noted by pilots.

Unless the RFI source is a strong signal, there is a possibility that it may not be detected on the ground, except in the immediate vicinity of the source. It may be necessary for the FMO to arrange airborne RFI support with the Technical Operations ATC Spectrum Engineering Services liaison at the NOCC for such investigation.

(1) Ground VOR RFI: This problem is mostly local and may be reported principally on an airport. In this case, it would be worth trying a ground search with the RFIM van on and around the airport first, or using a handheld DF system.

(2) Airborne VOR and LOC RFI: This problem is frequently from FM broadcast stations, especially if they are in the upper part of the 88 to108 MHz band, creating brute force and intermod problems in the airborne receiver when the aircraft nears the FM transmitter site. Unless the FM station is clearly identified by the reporting pilot, it will be necessary for the FMO or flight inspection crew to observe reception of the signal in the air. The following steps are recommended: (a) Flight Check: The FMO should join the flight inspection crew to make a definite determination whether a reported interference is really a problem or a problem in the reporting aircraft equipment.

(b) Air Traffic Check: Request the appropriate ATCT, TRACON or ARTCC personnel to query aircraft of opportunity to determine whether they notice a reported problem, before investigating a report.

(c) Confirm Reports: The FMO must confirm additional reports from aircraft utilizing the NAVAID service. The FMO shall seek for reports issued by other FI crews on the affected NAVAID.

(3) TACAN RFI: This type of RFI can be caused in two ways. Airborne reception can be affected by a source of interference somewhere on the ground. The ground based TACAN receiver can also receive interference from any source nearby on the ground or from any airborne source within RLOS. The FMO should work closely with the SMO frequency coordinator or SMO technicians if necessary so that the FMO can determine whether to work with the interrogator or the transponder frequency. Once the local geographical area is known, the FMO should proceed to locate the RFI source, using many of the techniques described in this chapter for interference to air/ground communications systems.

d. Radar Interference: This type of RFI requires collaboration with the concerned service area air traffic organization to identify. It is generally first noted by controllers. Interference to primary and its associated beacon present a particular problem in locating an RFI source.

(1) Primary radar RFI: Primary radar interference is normally another radar, although occasionally it is a harmonic from a lower frequency transmitter. The FMO should coordinate with SMO technicians to determine the azimuth the interference indicates on the air traffic controller’s scope. If the source is another radar, the interference may appear as dotted spirals named "running rabbits," which appear to "run" as the radar rotates. If the FMO has good records from the radar coordination program, the source might be identified by the PRR.

There is a method to determine this from the radar scope presentation and it is detailed in paragraph 1408.

Page 177 6050.32B Chapter 14 - continued 11/17/05 (2) Radar Beacon (ATCRBS or IFF) RFI: This type of interference is the most difficult of all because all interrogators and transponders work on the same frequency (1030/1090 MHz) and are separated only by PRR.

Interference is usually from another interrogator, which could be several hundred miles away. Interference will normally show up as intermittent false targets. This is because two different interrogators can illuminate an aircraft at nearly identical times, resulting in both radars "painting" both replies offset in time.

(a) Aircraft Location: It will be necessary to coordinate with the concerned service area air traffic organization to determine in what general area the aircraft are located which are producing the false targets. Once the area is known, monitoring of 1090 MHz should be done, looking for aircraft replies on the same PRR (±3 pps) as the victim radar. From there, it becomes trial and error plus deduction. Attempt to determine the direction of the victim aircraft. The area of search will have to be widened until an interrogator on 1030 MHz can be heard that matches the PRR of the victim. It is then located by DF procedures, as described in paragraph 1407.

(b) Beacon RFI: Since another interrogator almost always causes beacon interference, the FMO must exercise patience and diligence to locate it. The use of telephone contacts, particularly with DOD spectrum coordinators and appropriate on/off tests, are clearly indicated before a ground search is begun. Here is where the FMO's PRR coordination records, contacts set up in advance with DOD, other spectrum coordinators, and the telephone are usually the most valuable tools.

(3) Reflections: Awareness of reflections from metallic objects such as buildings, fences and the like can cause interference by putting the source radar signal into areas not intended. See paragraph 1302 and figure 13-1.

1406. DIRECTION FINDING (BELOW 1000 MHz) . After initial investigation procedures by means of telephone points of contact and record searching the next step to locate the potential source of RFI is to use DF equipment and techniques. There are three principal techniques, automatic DF, directional antenna DF, and proximity DF ("hot and cold" method). These techniques may be applied equally when used in an RFIM van, a standard vehicle mounted auto-readout or hand carried portable unit. Further details on these techniques could be found in the Radio Frequency Interference (RFI) Detection, Analysis and Resolution pamphlet referenced in paragraph 1400. This pamphlet could be obtained from Technical Operations ATC Spectrum Engineering Services in Washington, DC.

a. Automatic DF: Equipment and techniques of this type uses a set of ground plane vertical aerials, switched at a rapid rate, with a representative display of the incoming signal by compass rose showing a line of bearing strobe or numerical digital azimuth readout. Some automated systems make use of a computer, which allows for electronic data storage for later retrieval and analysis of the data. With automatic DF systems, the FMO follows the direction indicated by the line of bearing (LOB) on the display until the source is located.

Caution needs to be exercised when using these automatic DF systems since many false bearings may appear on the display due to signal reflections. It is recommended that the FMO continue to obtain LOBs while mobile to get out of zones that caused the reflections.

(1) RFID System: This is a portable unit that operates under the concept of a single channel Watson-Watt system that modulates the carrier with AM sidebands carrying the DF information. The RFID utilizes a series of multi-element adcock antennas for DF directional information where most of the processing is performed. In addition, the system is fully controlled by a laptop computer making it capable of unattended operation.

(2) PIMDS System: Like the RFID, this unit also operates under the concept of a single channel Watson- Watt system. The unit has RF combining circuits including the Sum/Diff Hybrids, and circuits that create the N-S, E-W, and Sense antenna patterns from the array inputs. In this unit, modulators and Gain/Phase equalization circuits modulate the N-S and E-W signals with low frequency tones, combining them with the sense signal.

The gain and phase vs. sense values are equalized over the frequency range to provide very accurate lines of bearing readings. This system is self-sustaining and does not require a laptop computer to operate. However, the computer can be added and unattended data collection can be performed.

Page 178 11/17/05 Chapter 14 - continued 6050.32B b. Directional Antenna DF: This type of equipment and techniques are frequently used because of the great availability of the equipment and its relatively low cost. The antenna is connected to a general-purpose monitoring receiver, which should include tuning in the aeronautical navigation and communications radio spectrum. For better results the equipment should have a signal strength meter. If a meter is not available, the aural signal intensity variance heard over the monitoring receiver speaker can be used. When a loop or dipole antenna is utilized, a signal null with respect to the source is of interest, because the null is much narrower (sharper) than the maximum signal reading. For a Yagi, Horn, or other high gain type antenna, the maximum signal reading is of interest. This is because of the radiation pattern of these particular types of antennas. The maximum lobe signal reading provides an unambiguous direction. However, the nulls in these kinds of antennas are varied and not diametrically opposed, so they may create confusion in determining the actual bearing.

Technical Operations ATC Spectrum Engineering Services manages the K95-100 series handheld system. This system is the most widely used by AF specialists and is available through the FAA Logistics Center.

(1) Loop Antenna: Electrically one half wave or less, the minimum signal is perpendicular to the plane of the loop. That is, when the loop is rotated, the signal meter or audio level will vary so that looking through the loop when the signal is nulled (i.e., at minimum level), it will indicate the bearing direction of the signal being received. A loop bearing is bi-directional. Since the loop null is symmetrical (when used within its design parameters), the source can be either in front or behind the loop. The procedure to determine the true direction to the source, after the first bearing has been taken, is to move at a right angle between one hundred and a thousand feet from the first bearing. Take another bearing. If the source is less than two miles away, the second bearing will cross the first bearing and thus establish a true direction ahead or behind. A third right angle measurement may be required if the source is at a considerable distance. Next, travel to the general area where the bearings intersect and take a third or fourth bearing. When this bearing is plotted, it should create a triangle with the first two. The source should be in or near the area enclosed by the triangle. Continuing triangulation will narrow the search area.

(2) Dipole Antenna: The handling process is similar to the one described for the Loop antenna but the indication is reversed. A dipole minimum or null is off the ends of the dipole, along its parallel plane. In effect, the dipole null is in the direction of (points to) the source. Because it is not electrostatically shielded like a loop, a dipole is subject to many more reflections. Caution must be exercise in following the bearings. Making frequent stops for additional bearing is recommended. Like the loop, the dipole is bi-directional. If it is not adjusted to resonant length it may not have symmetrical nulls. It is recommended that a chart showing the resonant length with respect to frequency be carried so that the dipole can be adjusted accordingly.

(3) Monopole (Whip) Antenna: The procedure is the same as the dipole. A whip is normally attached to the receiver antenna input connector. The receiver or antenna is rotated so that the plane of the whip is horizontal.

It is then used just as a less effective dipole. A whip can be used satisfactorily, if the signal is reasonably strong, or the receiver is very sensitive. In addition, a certain amount of directivity can be obtained by holding the receiver and antenna in front of the operator. As the operator rotates about on his/her vertical axis, one null may be more noticeable ("deeper") than the other. If this is the case, body mass is absorbing some of the VHF signal when it is behind the operator, so the "deeper" null could indicate the signal source is behind the operator.

(4) Yagi Antenna: A corner reflector or other multi-element type antenna is unidirectional. A signal strength meter on the receiver or other level readout must be used. The maximum received signal is of interest and used to determine a bearing to the source. The broad radiation pattern (“nose”) of the beam can be centered when a meter is used or other type of signal level readout. Nulls are asymmetrical, thus unusable. There are three advantages to a Yagi, corner reflector or beam antenna; (a) each produces gain, (b) each is unidirectional, and (c) each is polarized. Polarization allows for rotating the antenna on its directional axis to determine the signal source polarity or minimize reception of cross-polarity undesired signals.

Page 179 6050.32B Chapter 14 - continued 11/17/05 (5) Log Periodic: The procedure is the same as the Yagi antenna. This is also a multi-element type antenna that provides unidirectional characteristics. The same procedures used for the Yagi antenna for determining the bearing to the source apply to the Log Periodic.

(6) All Antennas: The antennas mentioned in this paragraph are effective. All should be operated away from metal or other RF reflective surfaces to prevent any reflections from giving erroneous or ambiguous bearings. It is recommended that 15 to 20 feet separation be maintained for a vehicle and up to 500 feet from a building. The loop is least affected due to its electrostatic shield. However, unless it is resonant at the frequency, it will provide some signal reduction over a dipole. Its static field shielding makes it superior for close proximity work. It is frequently beneficial to start with a dipole or Yagi until sufficient signal is received to use a loop.

c. Proximity DF ("Hot and Cold"): This technique is useful but a very time consuming and limited procedure. The technique consists of carrying a monitoring receiver either physically or in a vehicle, tuned to the frequency experiencing the interference. By trial and error, an area of maximum signal detected can be identified by observing the signal strength meter on the receiver as the unit is moved about. If the receiver has no meter or a meter is not available with suitable RF gain control, the alternative is to detune the receiver intentionally in the presence of a strong signal, which will give the appearance of a weaker signal to the receiver. By careful position selection or choice of moving from location to location, selective detuning, and other intuitive judgment the source could be located.

1407. DIRECTION FINDING (ABOVE 1000 MHz) . Microwave DF techniques are normally in the TACAN, Radar, MLS or RCL radio spectrum bands. There is no fine line at 1000 MHz. However, dipole and loop antennas become progressively ineffective for DF work above about 600 MHz and Yagis above 1,000 MHz. Log Periodic (LP) are more effective and Horn antennas start around 1000 MHz (1 GHz). These or helical equivalents are normally used, and because of antenna pattern configuration, the maximum signal is used for DF work. The new and future aeronautical navigation satellite service such as the Global Positioning System (GPS) will operate in the L band spectrum making the Log Periodic and Horn antennas the instruments of choice for DF work.

a. TACAN Type Signal: For this type of signal or other steady state emission, the source is located by triangulation as described in paragraph 1406. A Horn or Helical antenna is unidirectional, so even the first bearing taken indicates the initial unidirectional approach (allowing for reflections). A Horn is polarized (either vertically or horizontally), so it must be rotated on its directional axis to determine the polarization of the incoming signal. A Helical is not polarization sensitive, except where the source is reverse helical. In this case, the received signal is greatly attenuated by the reverse polarization of the receiving antenna.

b. Rotating Radar Type Signals: If the RFI signal is a rotating radar, the DF procedure is more complex.

Because the DF receiver is illuminated for only milliseconds every 4 to 12 seconds on the average, some means is required to denote small differences in received signal as the Horn direction is changed. If a field strength meter is used, the direct peak detection hold function should be used, since each illumination peak will be held for a few seconds. This allows visual noting and will permit signal level differences as small as 1 dB to be seen. If a general-purpose receiver is used, a high-speed recorder such as the TechniRite Model 711 attached to the Y output or detected signal will permit the same observation in real time.

(1) Horn/Helical Antennas: The horn or helical antennas should be positioned every 10 ° to 15 ° at a time and the received level noted. It is recommended to measure two or three passes at each azimuth before shifting the antenna. This will allow peculiar propagation such as beam fly-through by passing aircraft to be averaged out.

Peak azimuth readings should not be assumed as the bearing. A complete 360 ° check should be performed. The first peak measured may be a reflection or a minor lobe of the receive antenna. The real peak should stand out significantly. Another aid in discriminating between direct and reflected signals is that at microwave frequencies, reflected signals off flat surfaces shift polarity 90 ° , but reflections off rough surfaces such as mountains, may change anywhere between 0 ° and 90 ° .

Page 180 11/17/05 Chapter 14 - continued 6050.32B FIGURE 14-2. RADAR INTERFERENCE DF EXAMPLE (2) Radar RFI Example: A radar interference signal might be chased for miles in a continuing direction, only to find it to change abruptly concurrent with a marked increase in received signal strength. An actual example is shown in figure 14-2. The original bearings (1) through (4) in figure 14-2 all showed the same general area source and for 30 nmi converged on a point. This was because at the lower elevations, the only signal that the victim radar and the DF equipped vehicle could receive was that reflected from the mountain. But upon arrival near the converging point, the bearing suddenly shifted and the level greatly increased. The DF equipped vehicle’s receiver was now high enough to see over the hills that blocked direct reception of the interferer site.

The victim radar received its interference by reflection from the large 10,000 foot mountain.

1408. "RUNNING RABBIT" INTERFERENCE . Paragraph 1405 mentions the type of interference that occurs when two search radars of fixed PRR's are operated in proximity. The dotted line spirals, running out from or into the center of the radarscope display indicate this type of radar interference. It most likely would happen near a military base or training area where transient troop groups make frequent changes of radars. There is a formula which will allow the FMO to determine the PRR of the interferer radar, since the FAA PRR will be known.

a. Parameters: The first parameter needed is to determine whether the "rabbits," which actually are presentations of the difference in PRRs, are faster or slower than the FAA victim radar. The second parameter is the number of "rabbits" per radar sweep. The patterns for each condition are shown in figure 14-3. Shown below is the calculation for an interferer's PRR.

Page 181 6050.32B Chapter 14 - continued 11/17/05 FIGURE 14-3. RUNNING RABBITS PATTERNS b. When the PRR's are fairly close, ƒ = ƒ ± RS i v where; ƒ = PRR of interferer radar in pps i ƒ = PRR of victim radar in pps v R = Azimuth scan rate of victim radar in r/s S = Spirals/revolutions on victim radar scope presentations c. For Example: ƒ = ƒ ± RS i v Victim radar PRR = 360 pps Victim radar azimuth scan rate = 15 r/min = 0.25 r/s Victim radarscope presentation shows 6.0 spirals/revolution thus; ƒ = ƒ ± (6.0 x 0.25) i v ƒ = ƒ ± 1.5 i v f = 361.5, if the rabbits are as in presentation a of figure 14-3.

i f = 358.5, if the rabbits are as in presentation b of figure 14-3.

i Page 182 11/17/05 Chapter 14 - continued 6050.32B 1409. ELECTRONIC ATTACK (EA): DOD conducts frequent flights radiating for EA missions, covering very large geographic areas. In addition, the DOD conducts periodic GPS jamming test emissions. These emissions can be sources of serious RFI problems. The procedures are covered in chapter 18.

1410. POWER LINE INTERFERENCE . This type interference is difficult to locate. When power line generates ("carries") interference, it acts as a Beverage antenna and can conduct the RFI for miles along its lines as standing waves. (A Beverage antenna is one straight wire fed at one end that is many wavelengths long, usually 7 or more wavelengths. This configuration results in the antenna main radiation lobe being approximately in the same direction as the wire.) A motor arcing at a farm or factory can be the cause of the RFI. Arcing insulators on the power line are also potential causes. This type of problem is best solved by using a mobile system like the RFIM van or other suitable equipped vehicle and "cruising" the line coming into the facility, and other lines nearby.

a. Electric Motor Type: If it sounds like an electric motor, it could be from next door to several miles away, depending on how strong the brush arcing is and the amount of current drawn by the motor. Driving the RFI vehicle along the line feeding the facility will show a gradually increasing/decreasing average signal. Some frequent small increases in noise may be experienced as each power pole is passed. Using hot-and-cold DF techniques may lead into the area or the building with the source, which should be located within a reasonable period of time. When found, it should be brought to the attention of the operator, then of the utility company which supplies the service. Quick resolution may be accomplished when the FMO makes the operator aware of the impact to the safety of the flying public due to this RFI. Only fixing the problem at its source, probably with power line filters or additional or better grounding at the motor, can cure electric motor RF noise. In all cases, the FCC should be notified.

b. Intermittent Arcing: If it sounds like intermittent arcing, it probably is a cracked or broken insulator on a pole’s crossarm. The utility company should be notified, stressing the aviation safety of life and property risks.

The utility company may have an "interference" group, but if so, generally they are understaffed so that resolution may take a long time. The service area FMO should make an effort to locate the problem. If the FMO can locate it and report the pole to the utility company, resolution should be prompt. Since an arcing insulator can lead to a pole fire, a utility company normally will take immediate action. Use of the RFIM van or other suitably equipped vehicle to travel along the line is recommended. In the general area of the defective insulator, there will be a marked increase in RF noise. By carrying the portable receiver, the FMO can check the poles with the highest RF noise radiation. Standing next to the pole, a moderate blow with good-sized hammer will send sufficient vibrations up the pole to rattle the insulators. If the pole struck is the offender, the noise in the receiver will increase momentarily. On occasions, the arcing might even stop for a while until some other vibration sets it off.

Once it has been located, note the location and the pole number so that it can be reported to the appropriate utility company.

c. Ultrasonic Detectors: If available, an ultrasonic detector is a component of the RFI equipment complement. It is another tool that can be used with great efficiency in locating the arcing spot. After narrowing the area with a vehicle, the ultrasonic detector is pointed at individual cross-arms and insulators from the ground position. Since the detector uses a parabolic reflector, the ultrasonic source can be pinpointed by aural and level meter means via a bore sight, sometimes down to the specific insulator. When located, it should be reported promptly to the utility company with awareness notification to the FCC. Insulator arcing may occur at any time, but frequently starts after a long dry period when dust and dirt accumulate on the surfaces. The first rain, if heavy enough to clean the insulators thoroughly, may clear up the problem for a time. A light first rain after a long dry spell can make matters worse by washing dirt into a crack, setting up an even better arcing path.

Page 183 6050.32B Chapter 14 - continued 11/17/05 1411. DIGITAL RADIO SYSTEMS . Commercial digital radio systems, especially microwave links, are being implemented across the country. Because of the decreased resistance of some digital radio receivers to certain types of RFI, FMOs need to be aware that there may be increasing numbers of complaints from commercial vendors concerning RFI to their systems. FMOs receiving such complaints need to first evaluate the accused (FAA) interference source to assure that it is operating within specifications. If the FAA system is within parameters, then the FMO may help the commercial vendor in whatever manner possible, as long as no expense is incurred to the FAA. Special attention shall be taken on the Wide Area Augmentation System (WAAS) and Local Area Augmentation Systems (LAAS). These systems are satellite based navigation digital systems operating at very low-level signals. If the victim is a federal agency, including any of the military armed forces, plan to work with that agency in the same manner, but notify Technical Operations ATC Spectrum Engineering Services early on in the case for possible headquarters support.

1412. ELT PROBLEMS . Since their introduction, ELT's have caused a considerable amount of interference by false activations. Since they are on the emergency frequencies 121.5/243.0 MHz, they must be located and shut down quickly to keep the channels clear for legitimate ELT use by downed aircraft. Air traffic control facilities will be the first to know if a false activation occurs, since it mostly occurs on an airport. If it is very strong, the concerned service area air traffic organization should not only notify the Search and Rescue (SAR) personnel, the nearest ARTCC, and the service area duty officer, but also the appropriate SMO and the FMO. Most SMO offices have been supplied with hand carried ELT locators. They or other hand-held DF receivers can be used to locate the offending ELT. The hand-held K95-100 series DF supplied to service area FMOs and SMOs is an effective system for ELT location. Sometimes an accidentally triggered ELT may be in the trunk of a personal car, taken home by the pilot, or (as has happened) been set off by rough handling in shipping. An accidentally triggered ELT may be found at nearly any location, even far away from airports.

a. Procedure: The ELT must be silenced as quickly as possible. The FCC can be called for assistance, but this should be as a last resort and only if the FAA personnel cannot locate it themselves. Once found, it must be reported to the duty officer and the appropriate service area air traffic organization manager whose facility first reported it. By national agreement, all ELTs heard are assumed to be a downed aircraft until proven otherwise.

b. Aircraft ELT: If the ELT is located in an aircraft, do not enter it. The local General Aviation District Office (GADO) or Air Carrier District Office (ACDO) and the service area duty officer shall be notified as to the aircraft identification. It is their job to contact SAR and the owner of the aircraft to shut it down.

1413. RECORDS OF UNUSUAL PREVIOUS CASES . While all cases must be reported (see paragraph 1401), unusual or unique case records can provide a wealth of material which can be used to save time in resolving similar cases. All FMOs are requested to submit brief narrative descriptions of unusual resolved problems to Technical Operations ATC Spectrum Engineering Services so that they can be disseminated to other service area FMOs. The SMDb shall be used as much as possible to record these unusual events. In addition, audio tape recordings should be made of new or unusual cases and forwarded to Technical Operations ATC Spectrum Engineering Services for inclusion in the national RFI sounds bank. This sound bank can be found within the NAS RFI or GPS RFI modules of the SMDb for easy electronic file download. If the source has a particularly unusual video presentation on an oscilloscope or spectrum analyzer, a video tape of the RFI sent to Technical Operations ATC Spectrum Engineering Services would be useful and can be included electronically as part of the SMDb logged event.

1414. thru 1499. RESERVED Page 184 (thru 188)

11/17/05 6050.32B CHAPTER 15. RADIO FREQUENCY INTERFERENCE MONITORING VANS (RFI VANS) 1500. INTRODUCTION . The term "RFI Van" is the name historically used to identify the vehicles with specialized equipment, which are used for the location and resolution of radio frequency interference problems affecting the National Airspace System (NAS). The most recent generation of RFI Vans is known as the Radio Frequency Interference Monitoring System (RFIMs). The RFIMs are operated with or without engineering personnel to perform a certain set of measurements. The RFI Van vehicles have varied from passenger automobiles with basic RFI equipment, to Step Van vehicles, to large trucks with measurement electronic equipment housing power generating system to power it. In this order, the terms "RFI Van" or "Van" encompasses all those vehicles past, present and future including the new generation under the Transportable Interference Monitoring Detection System (TIMDS) program.

a. The RFI Van: This is an engineering tool with advanced automation used for the management of the radio spectrum. The RFI Van performs many functions in the Communications Navigation and Surveillance (CNS) area. In addition, Radio Frequency Interference resolution is an important part of its function. Figure 15-1 shows a block diagram of the equipment functionality used in the current RFIM.

FIGURE 15-1. RFIM FUNCTIONAL BLOCK DIAGRAM b. RFI Van Spectrum Monitoring: The spectrum used by the FAA has an increasing requirement to be continuously monitored. As more FAA facilities are added to the NAS, and transmitters from other services surround these facilities, the already congested spectrum becomes more crowded. Careful RF engineering must be performed to effectively use the portion of radio spectrum allotted to the FAA. The service area Frequency Management Officer (FMO) uses the capabilities of the RFI Van to monitor the spectrum environment in the service area and engineer its use effectively.

c. RFI Van National Program: Technical Operations ATC Spectrum Engineering Services established the Radio Frequency Interference Monitoring (RFIM) System to specify a standard RFI Van configuration for all FAA service areas. This program standardized the style and configuration of the vehicle, equipment and software for the RFI vans based on service area FMO office requirements. In addition, a comprehensive safety modifications program has been implemented for each service area RFI Van. The operation, control and maintenance is currently the responsibility of the service area FMO.

Page 189 6050.32B Chapter 15 – continued 11/17/05 1501. CONTROL AND RESPONSIBILITY . The service area Frequency Management Office has full responsibility for the operation and maintenance of the RFI Van assigned to their service area. The FMO schedules calibration of all RFI Van systems on a yearly basis. The FAA William J. Hughes Technical Center has established a national RFI Van modification and test facility in Atlantic City, New Jersey. Improvements, safety modifications, and software changes are coordinated through the RFI Van Engineering Change Proposal (ECP) process.

a. FMO RFI Van Planning: The Frequency Management Office plans and schedules the use of the RFI Van for providing electromagnetic radiation measurement and interference detection and location services to organizations having a need for it. System Management Office (SMO), Systems Operations Centers (SOC) or Operations Control Centers (OCC) specialists are required to coordinate with the service area FMO.

b. FMO RFI Van Familiarization: The FMO is the FAA representative thoroughly familiar with the technical equipment in the RFI Van, the practical applications of it, and possesses good knowledge of any facility equipment in need of test and measurement for which the RFI Van will be useful.

c. FMO RFI Van Coordination: The FMO operates the equipment in the RFI Van, records and analyzes measurement data, evaluates results, and prepares necessary documentation and reports. In addition, the FMO works closely with service area air traffic organization, SMO, and other concerned personnel to uncover, locate, and eliminate harmful interference. The FMO is the focal point for coordination with the FCC and other appropriate agencies in resolving harmful interference problems consistent with agency interests.

1502. RFI VAN USE . The RFI Van is outfitted with state of the art measurement equipment and automation tools, which can be used for radio frequency interference location and resolution. A variety of electromagnetic radio spectrum measurements can be accomplished. Some of these uses are: a. Antenna Radiation Patterns: The RFI Van system will measure and plot antenna radiation patterns while the facility under test operates normally.

b. Interference Detection: The RFI Van Direction Finding equipment provides Lines of Bearing (LOB) in the direction of an electromagnetic signal source.

c. Spectral Signature Measurements: The RFI Van Spectrum Analyzer equipment allows Fast Fourier Transform (FFT) measurements while the facility under test operates normally.

d. Frequency Measurements: RFI Van Frequency Counter equipment performs frequency tolerance measurements on facility transmitting equipment without disruption its operation for later adjustments.

e. Electromagnetic Surveys: The RFI Van automated software tools allow for electromagnetic compatibility and field strength measurements for facility coverage without disruption.

f. Radiation Hazard Measurements: Non-Ionizing radiation (i.e., thermal radiation) measurements can be performed for facility compliance with Occupational and Safety Hazards Administration (OSHA) standards.

1503. INSTRUMENTATION . The RFI Van is outfitted with a standard set of equipment and instrumentation to assure the capability of accomplishing the uses and functions listed in paragraph 1502. Additional equipment may be added temporarily at the option of the individual service areas for specific tasks that will require other specialized equipment. However, the core equipment is the following: a. Field Strength Meter: The FAA operates in certain portions of the radio spectrum, so it is essential that FMS equipment be properly calibrated for measuring the spectrum in which FAA operates. The RFI Van FMS measure frequencies from Low Frequency (LF) Non-Directional Beacons (NDB's) through Airport Page 190 11/17/05 Chapter 15 - continued 6050.32B Surveillance Radars (ASR) and Radio Communication Links (RCL). The Airport Surveillance Detection System (ASDE), Television Microwave Links (TML) and other new facilities can be measured as well. The four field strength measurement ranges are: (1) 100 kHz to 30 MHz.

(2) 30 MHz to 1000 MHz (1GHz).

(3) 1 GHz to 10 GHz.

(4) 10 GHz and above.

b. Spectrum Analyzer (SA): The RFI Van spectrum analyzer has a measurement frequency range from Very Low Frequency (VLF) 9 kHz to Super High Frequency (SHF) 26 GHz. The spectrum analyzer has X and Y outputs to record received signal spectra on a standard X-Y Plotter. In addition, computer interfaces allow for a standard commercial printer or plotter to be used. The Spectrum Analyzer also comes with the capability to add optional external mixer devices that increases the measuring range to millimeter wave. Like the field strength meter, the SA also must be calibrated so that it can be used in finite field strength and power density measurements.

c. RF Signal Generator: The RFI Van is equipped with a signal generator for generating test signals to be performed on site bench measurements of interest. The Signal Generator is capable of generating signals from 500 kHz to 1 GHz.

d. Frequency Counter: The RFI Van is equipped with a frequency counter with a range up to 1.5 GHz.

This equipment is usable for any counting function, however, it is particularly useful for measuring radar/beacon pulse repetition rates (PRRs) in conjunction with the field strength meter. In addition, it permits direct off-the-air measurements of high-level signals.

e. Step Attenuator: The RFI Van has accurate external step attenuators for increasing measurement equipment input attenuation with a range from 0 to 120 dB in 1 dB or 10 dB steps from 500 kHz through 26 GHz.

External Step Attenuator purposes are twofold.

(1) It can be used for dB step calibration of the X-Y Plotter and antenna pattern recordings.

(2) It can be used to insert basic attenuation before the field strength meter or SA to prevent its overload and operation at its greatest sensitivity, inhibiting AGC action, thus permitting linear readouts.

f. Antennas, Rotator and Mast: The RFI Van is equipped with a set of antennas to cover the radio spectrum capable of being measured by the field strength meters and SAs as mentioned in subsections a and b above. Generally, this will be loop antennas for the L/MF frequency range, frequency adjustable Dipoles, Log Periodic or Biconical antennas for 30 to 1000 MHz, and Horn or Helical antennas for 1 GHz and above. Yagi antennas for specific ranges are very effective. An antenna rotator mounted on the roof of the van allows rotating the installed antenna from inside the vehicle for the proper direction or polarization. The RFI Van is also equipped with a pneumatic mast that rises up to 40 feet.

g. Tunable Filters: The RFI Van is equipped with filters (i.e., band pass, notch, etc.) for at least the range 100 MHz to 3 GHz. The filters are interfaced or connected in front of the field strength meter or SA to eliminate instrument self spurious signal generated from the presence of very strong environmental signals other than the frequency being measured.

Page 191 6050.32B Chapter 15 – continued 11/17/05 h. Oscilloscope: The RFI Van is equipped with a scope for measuring rapid events, particularly rotating radar. It is also used for analyzing detected signals from receivers, field strength meters or SAs.

i. Audio Tape Recorders: The RFI Van is equipped with audio tape recorders for recording the sound of received signals. The unit is particularly useful in recording interference signals for evidence and later resolution.

The RFI Van computer workstation may also be used for this purpose if a sound card interface is available.

j. Aviation VHF Transceiver: The RFI Van is equipped with an air-ground aviation transceiver for communicating with Air Traffic Control Towers (ATCT) and Flight Service Station (FSS) on airports and with Flight Inspection (FI) aircraft during interference locating procedures.

k. Land Mobile VHF Transceiver: The RFI Van is equipped with a Frequency Modulated (FM) narrow band transceiver for communicating with SMO personnel at sites under investigation, in some circumstances with FI aircraft, and sometimes with the home base via the NRCS (C ) network.

l. Direction Finder: The RFI Van is equipped with a direction finder system capable of providing a line of bearing (LOB) in the direction of the source signal. This equipment is extremely useful when detecting and locating signals causing interference to FAA systems.

m. Printer and X-Y Plotter: The RFI Van is equipped with a commercially available Laser Jet quality printer. An optional X-Y Plotter may be used by the FMO conducting the measurements.

n. DC Inverter: The RFI Van is equipped with a commercially available direct current (DC) to 115 volts (V) alternating current (AC) inverter for powering low-drain ac powered equipment and charging NiCad batteries for accessory equipment in the van. The RFI Van vehicle battery supplies the DC source and is charged or "floated" by the van engine alternator.

o. Engine Generator: The RFI Van is equipped with a commercially available gasoline (or diesel) driven generator for 117 V AC of 1.5 to 3.5 kW capacity. This unit is used for supplying ac power to the larger drain units and used when the van is parked with its engine turned off and not charging the RFI Van battery.

p. Ancillary Items: Service area Frequency Management Offices may from time to time use a number of ancillary items as follows: (1) Step-recovery diode for extending the frequency meter and generator output to at least 3 GHz for accurate radar and beacon frequency measurements.

(2) Broadband amplifiers for at least 100-1,000 MHz, to permit increased signal level to drive the step recovery diode for microwave measurements above 1 GHz.

(3) Ultrasonic narrow beam detector for locating specific defective insulators or crossarms on power poles which cause arcing and resultant broadband interference.

(4) A Citizens Band (CB) transceiver for receiving road advisories when the RFI van is on long trips.

(FMOs are reminded that CB may only be used for receiving information, and not transmitting, unless there is a road emergency involved.)

(5) Family Radio Service (FRS) FM Transceiver for intercommunicating with the RFI Van personnel or during interference location coordination.

(6) Extra Step Attenuator for additional signal attenuation when in close proximity of high emitters.

Page 192 11/17/05 Chapter 15 - continued 6050.32B (7) Altimeter and Compass for altitude and azimuth determination with respect to the measured site.

(8) A radar beacon transponder mounted in the van, used only to work with a service area air traffic organization and Flight Standards to positively locate the van on a radar scope when working on radar measurements or interference problems.

(9) Global Positioning System receiver for determination of precise position in latitude and longitude at the location of conducting measurements.

(10) A cellular telephone for contacting other agencies such as the Federal Communications Commission or Law Enforcement as deemed necessary.

1504. RFI VAN SYSTEM OPERATION . Operating the various systems in the RFI Van requires knowledge, training, and skill. While there are several independent systems, they all merge into one total monitoring and measuring system. The FMO must remember that measurements and follow-on documentation is very important for the various agency and service area programs. The FMO's work may be presented as evidence in court. Thus, all measurements and documentation resulting must be handled within the highest professional standards.

a. The RFI Van measurement control system (MCS): The MCS is an easy-to-use program for computer controlled field frequency measurement. A selection of canned measurements is available which requires a minimum of user input. The canned measurements are the simplest way to take RF measurements, and those canned measurements include most of the measurements required by the FAA. The MCS can perform an RF path calibration and use the results to adjust measurement values to account for the changes in system gain at higher frequencies. FMOs may also manually set up the instruments, and then use the MCS software to capture the instrument settings and data on the computer hard drive. The MCS has been written in LabVIEW® 5.0 under the Windows 95® operating system with many menu driven functions. Technical Operations ATC Spectrum Engineering Services has developed a comprehensive training course for the use of this automated tool. The following paragraphs will deal mostly with instruction and examples of each system operation from a general perspective. See Figure 15-2.

FIGURE 15-2. MCS CANNED MEASUREMENTS STARTUP SCREEN Page 193 6050.32B Chapter 15 – continued 11/17/05 1505. RADAR AND ATCRBS ANTENNA PATTERN RECORDING . Radar antenna pattern recording is a valuable product of RFI van measurements. It permits actual radiation pattern recording from any point in space the measuring equipment can be located. It can be accomplished without the radar having to shut down or make any changes in its normal operation, unless the measurements are made to allow various patterns to be measured as the antenna or transmitter functions or hardware are changed. Done correctly, the measurement permits the FMO to determine whether the radar and beacon radiated patterns are normal as well as the directional and nondirectional pattern ratios of SLS operation. The FMO can make this determination on site, within the time it takes to record one revolution of the radar antenna, usually between 5 and 15 seconds. The results then can be transmitted to the site, to the SMO, or the OCC, so that a decision can be made immediately. An SA with printer or a computer controlled spectrum analyzer (CCSA) with a printer provides superior results.

a. Primary Radar Antenna Pattern Plotting with field strength meter/X-Y plotter: This is a basic measurement and requires only these devices: a receiver (including an SA), a high-speed recorder, a calibrated step attenuator and a suitable calibrated antenna with a stable mount. NOTE : The procedure below is specifically for a field strength meter as the receiver, but use of an SA will be similar except for some steps. Many SAs can be manually tuned which simulates manual tuning of a field strength meter. See figure 15-3.

FIGURE 15-3. RECORDING SETUP AND SAMPLE TAPE (1) Set the step attenuator to its highest attenuation (80 to 120 dB) to prevent damage to the field strength meter from high-level signals.

(2) Connect the appropriate Horn antenna to the input of the attenuator, with the output of the attenuator connected directly to the input of the field strength meter.

(3) Set the field strength meter internal attenuators to zero, to prevent AGC action from giving nonlinear readouts.

(4) Set the antenna for proper polarization. If in doubt, try both horizontal and vertical polarization of the horn and use the one giving highest signal level. Usually, there is about a 15 dB difference between correct and reverse polarization indications. Adjust the azimuth to approximately the radar direction.

Page 194 11/17/05 Chapter 15 - continued 6050.32B (5) Tune in the radar on the field strength meter. This probably will require carefully reducing the step attenuator in 10 dB steps while tuning the radar frequency. Adjust for on-scale meter and recorder by noting the peak pass recorded on the recorder. The direct peak function of the field strength meter can be used for this careful tuning process if the recorder is turned OFF. If a Spectrum Analyzer is used this step will be equivalent to the Max Peak hold mode.

(6) Set the field strength meter bandwidth to 1 MHz or nearest value.

(7) Carefully rotate the antenna in azimuth for maximum signal to the field strength meter. This will take a little time since the signal will be varying widely in intensity as the radar rotates. Increase the step attenuation if it becomes necessary to keep an on scale reading.

(8) Set the field strength meter function to quasi-peak or slide-back peak. The goal is to obtain a time constant of 10 msec without "dump." NOTE : In direct peak function, the EATON NM-65T field strength meter will inject a reverse voltage at the end of the store time to restore the meter to a low value quickly to get ready for the next peak pass. The high-speed recorder will slam against its lower reference level and could be damaged due to the large reverse voltage applied. The field strength meter, with its slow ballistics due to damping, will not be slammed.

(9) Connect the high-speed recorder to the Y or signal output of the field strength meter. NOTE : If the recorder has been carefully calibrated before, only a quick check of levels would be required. If not, calibration must be done at this time before any of the instrumentation controls are touched. Calibration of the high-speed recorder is discussed in paragraph 1506.

(10) Adjust the attenuator so that a near maximum scale reading is received when the radar is "search- lighting" the RFI Van, the maximum signal to be received.

(11) Record at least one full pass of radar illumination, with two or three consecutive being preferable to average out any anomalies or reflections in propagation, such as aircraft flying through, a passing vehicle's ignition noise recorded, etc.

(12) Analyze the recording briefly and advise Technical Operations Services or service area air traffic organization personnel waiting for the information. Retain the recording for follow-up detailed analysis and documentation.

b. Primary Radar Antenna Pattern Recording with a CCSA: When the Computer Controlled Spectrum Analyzer (CCSA) is coupled with a standard printer it will provide superior results. The basic setup is similar to field strength meter/X-Y plotter, except the measurement components are replaced with a Spectrum Analyzer and associated standard printer. The 12 steps listed in paragraph 1505a above are applicable. Careful attention should be taken in the steps regarding preventing overload and nonlinear readout for the SA just like for the field strength meter. The advantage is that the CCSA does its own internal calibration and prints these values as well as the grid scale values on the print out. Expanded prints of the radar beam can easily be obtained by merely programming the CCSA before a recorded or stored pass. Examples of CCSA printouts (reduced from a standard 8½" x 11") are shown in Figure 15-4.

Page 195 6050.32B Chapter 15 – continued 11/17/05 FIGURE 15-4. EXAMPLES OF ANTENNA PATTERNS ON CCSA PRINTOUTS c. Beacon Antenna Recordings: These are done the same way as mentioned in 1505a and 1505b, except for two conditions. The field strength meter or CCSA bandwidth cannot be less than 1 MHz to prevent the possibility of signal processing error due to the difference of pulses transmitted by the directional and omni-directional antennas. Two plots must be made, one immediately after the other, with the SLS omni on, then off. This allows the FMO to assure that there is no "punch through" of the directional signal on the normal SLS radiated pattern.

d. Pattern Recording Considerations: The previous list in paragraph 1505a of "how to perform measurements" gives instruction on the actual recording process. However, every bit as important is the special considerations that must be evaluated for each measurement.

Page 196 11/17/05 Chapter 15 - continued 6050.32B (1) Knowing the monitoring site location with respect to the radar being measured is very important.

Using maps for azimuth and distance and the on board altimeter, a close estimate of location can be obtained. If the RFI Van has a beacon transponder and previous arrangements have been made with the service area air traffic organization, a reading of the transponder's distance and azimuth from the associated radar coupled with the on board altimeter, can give an exact location of the RFI van. Use of a GPS receiver is recommended.

(2) From the location determination, the vertical angle between the monitoring site and the radar antenna site can be calculated. This is critically important. If the site is at 0 ° vertical angle or lower to the calculated vertical angle of the radiated beam, the recording and resultant plot should be considered as reference only. It is useful for checking radiating patterns at later dates, but should not be submitted as the actual pattern. This is because the beam "nose" will be above the recording site, and thus all references to signal levels, which are used to plot the ultimate pattern, will not have the correct "nose" reference and will be faulty. Below 0 ° , the antenna pattern cuts off rapidly, while above 0 ° it falls off slowly so that only very little error ensues, even for a few degrees. A site vertical angle of a degree or so above the beam line is best.

(3) An elevated monitoring position is essential. However, in mountainous terrain, reflections can lead to false levels at some azimuths with respect to the radar. When in mountains, make a second recording a few feet or a few hundred feet away, to assure the first site was a valid non-reflective site and vice versa. A quick comparison of the two recordings can determine any appreciable differences.

(4) When a good monitoring site is not available, alternatives must be considered. Sometimes the top of a building can provide a suitable site, if the measurement is made from the roof edge nearest the radar to reduce or eliminate reflections. If the radar antenna is not mounted too high, a "cherry picker" can be used to get to the proper height. In this case care must be taken to assure that the field strength meter is properly shielded to provide a sufficient dynamic range of recording. Verify by placing a metallic cover cap or shorted coaxial connector over the antenna input terminal. If a signal level is recorded it should be due to leakage. If that peak level with the cap over the input terminal is 40 dB or more below the level indicated with the Horn antenna connected normally, the recording can be considered accurate, at least down to that level. If none of these alternatives are possible, then the situation of a "reference only" recording must be considered. Helicopters and aircraft have been tried, but have not given good results due to the instability of the measurement platform for the period of antenna revolution.

1506. HIGH-SPEED RECORDER CALIBRATION AND OPERATION . The following are the general recommended procedures: (See figure 15-3) a. Calibration . Setting the zero and span controls is necessary to establish levels that can be relied upon from measurement to measurement. A calibration can be accomplished right on the tape itself. This is done by using the incoming signal, which is recorded as the source for calibration of this recording only. After normal pattern recording, slow the tape speed to the slowest practical. While the tape is recording, insert successive 10 dB steps of attenuation between each illumination so that each pass represents 10 dB less level. Adjust the span control so that the 10 dB marks coincide with the tape horizontal lines.

b. Operation . Depending on the speed of antenna rotation, the tape pull rate should be 25 or 50 mm/sec.

This allows a good resolution of higher speed ASR plots, while still not making the ARSR plots too long physically. If the recorder has easily changed speed ratios, it is most beneficial to be able to reduce the rate to 5 mm/sec or so when calibrating or tuning the system. This allows accuracy in reading the peak recorded, yet does not waste yards of tape for those functions. If speed change is not easily done, the recorder can be turned off between radar passes for calibrating, to save recording tape.

c. Documentation . While the FMO now has a completed tape, it should be incorporated into a technical report of the operation. Reproduce the tape as recorded, but include calibration marks so that anyone can read it.

In addition, affix an identification label, which includes date, time, location, source and any other pertinent data.

Page 197 6050.32B Chapter 15 – continued 11/17/05 The calibration should be shown directly on the tape, with the "nose" of the pass indicating 0 dB and other declining dB levels as minus, e.g., -10 dB, -20 dB.

1507. SPECTRUM ANALYSIS . Spectrum Analysis of any segment of the radio spectrum is valuable for planning and problem solving and can be done in three ways. One uses a spectrum analyzer with photographs taken of the scope presentation. The second uses a field strength meter and X-Y plotter. The third uses the CCSA system to do it all.

a. Spectrum Analyzer Photographing: Taking a photograph of a rotating radar is relatively easy to obtain, but generally does not yield as high a resolution as capturing the data with X-Y Plotter or Computer Controlled SA printer. The following steps are recommended: (1) If the antenna is stationary, plotting is easy. Merely scan the portion of the spectrum desired. Then use a scope camera and take a picture of the spectrum appearing on the screen, but allow aperture opening long enough to obtain a full scope sweep.

(2) If the antenna is rotating, it will be necessary to perform two steps. Allow several passes to accumulate on the screen in the storage mode before taking the scope picture. Open the camera shutter while it is on the scope and allow several passes (6 to 10 is recommended) to allow the camera to act as the storage medium.

An example of a spectrum picture from a spectrum analyzer is shown in figure 15-5.

FIGURE 15-5. PHOTO OF SPECTRUM FROM A SPECTRUM ANALYZER b. Computer Controlled Spectrum Analyzer: There are great advantages in using this approach. The results are readily seen in the reduced size spectrum plot shown in figure 15-6. Here, the amplitude (Y axis), frequency range (X axis), bandwidth, storage time, and all essential parameters are transmitted to the computer via a computer interface. Upon command, it simply stores, then prints or plots the results.

Page 198 11/17/05 Chapter 15 - continued 6050.32B FIGURE 15-6. CCSA PRODUCED RADAR SPECTRUM PLOT c. X-Y Plotter Recordings: These are much more complicated to do, but provide much greater resolution, particularly if a CCSA system is not available. However, the process of setup is complex and requires some explanation.

(1) The X-Y Plotter essentially takes an X-axis variable voltage to provide the frequency base of an X-Y plot. As the field strength meter is tuned from a reference frequency to a higher frequency, the X output voltage increases in a linear manner with respect to frequency. Once the frequency range to be scanned is established, the FMO must then set up the plotter so that its baseline represents a calibrated frequency line.

(2) Most field strength meters have variable output X voltage directly proportional to frequency. That is, on a 1 to 10 GHz frequency range, the field strength meter linearly provides 1 to 10 V dc for the X-Y plotter X- axis. The problem is that the X-Y plotter normally has only a 0 to 1 V recording range and a dc "bucking voltage" capability is required to permit zeroing the left edge of the plot when the field strength meter X output voltage is greater than 1 V.

(a) Assume an ASR spectrum is to be plotted and it is desired to plot from 2650 to 2950 MHz. That means that when the field strength meter tunes from 2650 to 2950 MHz to cover the whole page, the X voltage supplied the X-Y plotter will be 2.65 to 2.95 V dc, respectively. But since the X-Y plotter is designed to only handle 0-1 V dc and it can only "buck" 1 V dc, the recording would be impossible. The recorder would be hard against the right margin trying to reach a nonexistent 2+ V position.

(b) The solution is to provide an in-line variable "bucking" voltage. This can be accomplished by placing a 10/1 voltage divider across the X output of the field strength meter. But this is not the most recommended approach. Some X-Y plotters draw significant current through their X inputs, since it is only a variable voltage divider in the first place. Any additional voltage divider then would be very nonlinear.

(c) A better solution is to build a stable and variable "bucking" voltage source to be placed in line with the X output of the field strength meter. The basic dc sources can either be an ac driven transformer low ripple dc supply, or a simple battery with a Zener diode. With the battery, of course, provision must be made for shutting off the battery when not in use. A schematic diagram of a suitable "bucking" device is shown in figure 15-7.

Page 199 6050.32B Chapter 15 – continued 11/17/05 FIGURE 15-7. A DC BUCKING VOLTAGE SYSTEM FOR X-Y PLOTTERS d. Calibration: Calibration of an X-Y plot is a process that takes some time, but takes less as the FMO becomes familiar with it.

(1) Connect the "bucking" voltage in reverse series.

(2) Turn on the field strength meter and tune to the LOWEST frequency to be scanned V.

(3) Connect the X and Y outputs of the field strength meter to the X-Yplotter.

(4) Turn on the X-Y plotter with the pen lifted. Unless by chance the "bucking" voltage and field strength meter X output voltage are nearly identical, the pen will go hard left or right. Immediately adjust the bucking voltage control to bring the pen on scale.

(5) Use the X-Y plotter zero control as a vernier to put the pen on the zero left hand mark of the paper being recorded upon.

(6) Tune the field strength meter to the HIGHEST frequency to be plotted.

(7) Now adjust the X-Y plotter span control so that the pen is on the right hand mark of the paper to be recorded upon.

(8) Tune the field strength meter to the LOWEST frequency to be recorded again and note the position of the pen. Most likely, it no longer will be on the zero mark previously set. This is because there is some interdependence between the two controls.

(9) Tuning the field strength meter between the two limits of frequency to be recorded, carefully "jockey" the zero and span controls until the pen exactly coincides with the frequency span of the field strength meter between minimum and maximum frequencies to be recorded.

( 10) To improve the frequency accuracy of the base line of the plot, it is wise to inject a small signal from the signal generator into the field strength meter to positively locate an accurate frequency mark on the plot.

For instance, if 2700-2900 MHz were being recorded, it would be wise to inject alternately 2700 MHz then 2900 MHz with the "jockeying" so that the two ends are accurately marked. With the linearity of the X output, the frequency marks from the grid paper on the plotter can be assumed to be reasonably accurate.

e. Y Axis Setup: The following steps are recommended: (1) Set the field strength meter function to "Log" .

Page 200 11/17/05 Chapter 15 - continued 6050.32B (2) With the field strength meter tuned off frequency or the input temporarily disconnected so that the pen will drop down to its lowest voltage level to be recorded, adjust the Y axis zero control so that the pen is a quarter of an inch or so above the bottom line on the grid paper.

(3) With the pen still up , carefully tune the field strength meter to the center of the radar frequency.

(4) Adjust the X-Y plotter Y output control so the peak of the pen sweep on illumination by the radar goes up to 75 or 80 percent of full scale.

(5) Set the IF bandwidth to 0.5 or 1.0 MHz.

(6) Tune the field strength meter to the lowest frequency to be recorded (all the way to the left of the paper grid) and recheck the X-axis zero level to assure no drift has occurred while setting up. Readjust zero and span if necessary.

f. Plotting: The following steps are recommended for the plot: (1) Tune the field strength meter to the start frequency and lower the pen to the paper. Allow sufficient time for at least one pass of the radar beam .

(2) Carefully move the tuning a very small increment and wait for another pass. It is important not to move the tuning while the beam is illuminating the van. Time the moves so that they are made near the back lobe pass. It is essential that once a plot has begun, tuning be continued in the same direction. There are both electrical and mechanical backlash, however small.

(3) Continue advancing the frequency in very small increments until a definite pass is indicated. Then move in increments small enough to give the resolution desired. When tuning is nearing the peak, reduce the advances to very small amounts, about the width of a pen stroke, to assure a very high-resolution plot.

(4) Continue to the end of the plot space. Lift the pen.

(5) When the plot is completed , tune the field strength meter back past the peak. Then carefully approaching from the same increasing direction, precisely tune in the peak again. LEAVING ALL OTHER CONTROLS UNTOUCHED, use only the X zero control to move the pen to almost the left edge of the paper grid.

(6) Drop the pen onto the paper for just one pass, then lift it quickly again.

(7) With the X zero control , move the pen just slightly to the right.

(8) Using only the in-line attenuator , add 10 dB of attenuation.

(9) Lower the pen and record one pass. Lift pen. Repeat these sequences until the attenuated peak pass signal is at a very low level, but not lower than -70 dB or so. It will be less if the plot is started well into the emitted spectrum. The plot is now completed.

g. Documentation: As with the antenna plots described before, the completed spectrum plot needs to be properly labeled and identified. Frequency marks should be placed at the bottom of the plot, at appropriate locations. Using the amplitude calibration marks, horizontal lines should be drawn to indicate levels. A sample plot is shown in figure 15-8.

Page 201 6050.32B Chapter 15 – continued 11/17/05 h. Discussion: Figure 15-8 provides a highly defined emitted spectrum plot, accurately keyed to a frequency base. In essence, the field strength meter has acted as a very slow-moving focal plane shutter camera, imprinting a "slice" view sequentially on the paper. The reason for the on-plot signal source calibration is twofold: (1) It verifies the accuracy of the spectrum plot at time of review .

(2) It integrates all the limiting factors (any lost signal due to reduced bandwidth, ballistic drag of the plotter pen drive system, etc.) so that the spectrum overall accuracy is assured.

(3) If only 50 to 60 dB dynamic range is required , the 10 dB steps will be quite linear. But if a larger dynamic range is desired, it will be necessary to compress the upper 10 dB, in order to accommodate the wide dynamic range. This is because most field strength meters have only a 60 dB dynamic meter range. There might be small non-linearities noted between 10 dB levels. A check on any steady signal, using a similar on plot calibration verified by comparison with the field strength meter panel meter, may show that the in-line attenuator may not be perfectly linear, but should be < ±2 dB.

i. Signal Stability: If the signal being plotted has a stable level such as a radar "searchlighting" the RFI Van (or a VOR or TACAN) the same procedure would be used, except the tuning could be done slowly but continuously, completing the plot in a minute or so. If the field strength meter has automatic frequency scan, that could be used, so long as the scan rate is slow enough to allow the damped pen to respond accurately to variations as it is moved across the page.

FIGURE 15-8. SAMPLE SPECTRUM PLOT OF A ROTATING RADAR 1508. FREQUENCY MEASUREMENTS . Frequencies usually are measured in one of two basic ways. The first is by direct means, the second by indirect means using a transfer standard. Both are easily accomplished with the RFI Van.

a. Direct Measurements are done simply by using a frequency counter or frequency meter. The incoming signal is fed to the frequency counter and read directly.

Page 202 11/17/05 Chapter 15 - continued 6050.32B b. Indirect Measurement method uses a signal generator or other frequency meter and a receiver or SA.

The desired signal is tuned in on the receiver or SA. An accurate calibrated signal source is also fed into the same receiver or SA through a variable attenuator, so that an appropriate ratio between the signal and the generator can be set. By vernier adjustment, the generator is adjusted to exactly the center of the spectrum distribution peak. In cases of a very strong signal to be measured, the signal is centered in the pass band of the receiver or SA scope.

The signal is temporarily removed and the generator is fed to the receiver directly. The generator is then centered on the receiver or SA scope and the frequency read from the generator or from another accurately calibrated source measuring the generator. Most CCSA's have frequency measuring functions built in, either a marker with frequency is shown or the center frequency on the screen is measured and printed out in the spectrum plot.

c. Extended Indirect Measurement is usually used only for frequencies above 1 GHz, unless a very accurate signal generator is available for the microwave range. Most combination signal generators and frequency meters cover from lower frequencies up to about 1 GHz. To measure frequencies accurately above 1 GHz, the lower frequency generator is used, driving a step-recovery diode. This set up permits abundant harmonic output of the driving generator frequency and carries its level of accuracy. However, a step-recovery diode needs in excess of 1 V of RF to push it into harmonic generation. Using whatever generator is available in the van, add a small microwave amplifier, which in turn drives the diode with 1+ V, which will produce th harmonics up to the 10 .

d. Example: For instance, an accurate measurement of 2755 MHz can be done using the transfer standard th method by generating a 275.5 MHz signal, with the output signal at 2755 MHz at the 10 harmonic. Other harmonics are generated as well, so care must be taken to ensure the right harmonic is being used. Accuracy of the 2755 MHz signal will be equal to the signal generator, e.g., if the signal generator is accurate to .00001 th percent, the 10 harmonic will also be accurate to .00001 percent.

e. Accuracy Resolution: This factor must be considered. Even though a meter or counter might have a 9 or -8 10 digit readout, the manufacturer's accuracy specification must be adhered to. A measurement of 10 resolution -6 is meaningless if the instrument is only accurate to 10 . For example, an indicated measurement of 110.05061 -6 MHz on an instrument of only 10 accuracy should be rounded off to 110.051 MHz to be commensurate with the instrument's limit of accuracy.

1509. OFF THE AIR PRR MEASUREMENT . Pulse Repetition Rates (PRR) can be measured off-the-air in several ways. The following are recommended: a. Direct Pulse Rate Measurements: Direct pulse rate measurement instruments provide reasonably accurate PRR measurements by sampling a radiated spectrum, removing the pulse elements, and automatically predicting the total rate per second. Sampling rates can be as short as 50 μ secs. These instruments are very expensive.

b. Detected Pulse Rate Measurements: The detected pulse rate measurement is commonly used. The process consists of taking detected video from the output of a field strength meter or SA and feeding it directly to a frequency counter. Most simple counters are designed for CW signals and may not respond well to a pulse signal. One way to solve this is to take the detected video and feed it first into a resistor/capacitor (RC) time delay circuit which will somewhat approximate a sine wave, then to the counter so it will read accurately.

(1) A Time Constant (TC) circuit , formed by a 10K ohm resistor and a 0.25 microfarad (μfd) capacitor will frequently be sufficient without reducing the signal too much. The FMO should experiment with a steady state pulse signal, while watching it on a scope, varying the TC to produce a reasonable replica of half a sine wave. Signal shaping which will give stable PRR readout is the goal .

Page 203 6050.32B Chapter 15 – continued 11/17/05 (2) A varying pulse signal , such as from a rotating radar, requires that the gate time of the counter be varied so that it does not include the actual searchlighting of the van. This large change in signal level can upset the gate counting cycle and give an unrepeatable PRR.

c. Oscilloscope PRR Measurements: These kinds of measurements are also very useful for widely varying amplitudes of signal.

(1) In one use , the video output of the field strength meter or receiver is fed to a calibrated scope. The sweep is set to trigger on the leading edge of a pulse. By adjusting the trigger level, a quite stable pulse presentation can be presented on the scope. The pulse period can be determined from the scope graticule and its calibration. The PRR is simply the reciprocal of the period. The accuracy is limited by how accurately the pulse -6 period can be read. For example, a period of 2700 μsec measured would translate into 1 ÷ (2700 X 10 ) = 1 ÷ .0027 = 370.3, or approximately 370 pps.

(2) In another use , the video output of the field strength meter or SA is fed to channel 1 vertical input of a two-channel scope. Using a function generator set for triangular wave output, connect it to channel 2 vertical input of the scope and a frequency counter. Set the trigger to channel 1. Refer to figure 15-9 for a typical setup.

Either use the scope ADD function or position each of the channel presentations so that the detected pulse rides the peak level of the triangular wave. Adjust the triangular wave frequency until two consecutive peaks exactly match two consecutive pulses. Read the PRR from the frequency counter. Figure 15-10 shows correct and incorrect presentations for accurate measurement conditions.

FIGURE 15-9. BLOCK DIAGRAM OF ONE METHOD OF MEASURING PRR Page 204 11/17/05 Chapter 15 - continued 6050.32B FIGURE 15-10. SCOPE DISPLAYS FOR CORRECT AND INCORRECT MEASUREMENT 1510. thru 1599. RESERVED Page 205 (thru 214)

11/17/05 6050.32B CHAPTER 16. IONIZED AND NON-IONIZED RADIATION MEASUREMENTS 1600. PURPOSE . This chapter specifies the procedures and considerations for ionized and non-ionized radiation measurements to be made by the FMO.

1601. GENERAL . Order 3900.19B, the FAA Occupational Safety and Health Program, assigns specific responsibility in the area of radiation safety and provides reference criteria for ionizing and non-ionizing radiation exposure. The FMO is responsible for the actual definitive measurements of radiation levels as specified in Order 3900.19B. Detailed measurement procedures are contained in later sections of this chapter. [Previously, Order 3910.3A, which was cancelled by Order 3900.19B, set Permissible Exposure Limits (PEL) for all Radar, Tactical Air Navigation (TACAN), Air-to-Ground communications (A/G), National Radio Communications System (NCRS), etc., for frequencies from 0.3 MHz – 100 GHz]. Order 3900.19B adopted the most current version of the Institute of Electrical and Electronics Engineers/the American National Standards Institute (IEEE/ANSI) standards (the 1999 Edition of C95.1) for uncontrolled non-ionizing environments and the most current version of the American Conference of Government Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs) for Non-Ionizing Radiation for controlled non-ionizing environments. In lieu of using the term PEL, the non- ionizing exposure limits are called Maximum Permissible Exposures (MPE) in the 1999 Edition of IEEE/ ANSI C95.1 and the TLVs in the ACGIH document. Both are specified in units of milliwatts per centimeter squared (mW/cm²). Order 3900.19B also adopted the latest version of the ACGIH TLVs for ionizing radiation. The most current version of these standards available at the time of a survey shall apply.

a. Technical Operations ATC Spectrum Engineering Services is an important element within the FAA for performing radiation hazard measurements, both ionizing and non-ionizing. Technical Operations ATC Facilities, Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services will perform routine ionizing and non-ionizing radiation surveys for the purpose of accumulating data to use in the exposure assessments. A Letter of Agreement (LOA) for the division of functional Radiation Safety Program (RSP) Responsibilities was developed and agreed upon in September 2002 between the former FAA organizations Spectrum Policy and Management Program (ASR) and the Resources Management Program (AFZ). An update of this LOA is presented in figure 16-6 for reference. Figure 16-1 provides an outline of the process to be followed in making a radiation hazard measurement, consistent with the LOA.

Page 215 6050.32B Chapter 16 – continued 11/17/05 FIGURE 16-1. PROCESS FOR OBTAINING A RADIATION HAZARD MEASUREMENT Spectrum Engr.Services Note 1. Appropriate HQ Program Office will request Technical Operations ATC Spectrum Engineering Services to conduct a baseline measurement.

Note 2. All requests for special RADHAZ measurements, other than those for commissioning, baseline, and routine will be referred to the ROSHM who will then refer to their service area FMO.

Note 3. For commissioning and/or equipment modifications, the appropriate service area program office will request that the service area FMO conduct a RADHAZ measurement.

Note 4. Technical Operations ATC Spectrum Engineering Services will either conduct the measurement or determine what resource to use to conduct it: the Mike Monroney Aeronautical Center, the William J. Hughes Technical Center, the service area FMO, or contractor. All measurements will be coordinated with Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services. Refer to the Letter of Agreement, 7-29-05 (figure 16-6), Technical Operations ATC Facilities item number 4, for Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services measurements.

(Notes continued on next page) Page 216 11/17/05 Chapter 16 - continued 6050.32B (FIGURE 16-1 notes, continued) Note 5. Upon receipt of a special request for a RADHAZ measurement, the FMO will work with Technical Operations ATC Spectrum Engineering Services. For commissioning or equipment modifications, the FMO will notify Technical Operations ATC Spectrum Engineering Services and conduct the measurement.

Note 6. The following offices will receive a copy of the report: Technical Operations ATC Spectrum Engineering Services, Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services , the ROSHM, and the SMO. Technical Operations ATC Spectrum Engineering Services and/or the FMO will immediately notify Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services and the ROSHM when the measurements indicate radiation at or above the "Action" levels. Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services will initiate medical interpretation and related follow-on actions.

b. Technical Operations ATC Spectrum Engineering Services will be responsible for ensuring the ability to perform radiation measurements in a timely manner, to include training of Technical Operations ATC Spectrum Engineering Services engineers and service area FMOs.

c. Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services has overall program management responsibility for environmental hazards, including radiation hazards.

d. On an infrequent basis , it may be necessary for the FMO to perform a radar antenna pattern measurement by solar means in order to advise on the radar antenna tilt angle to resolve RADHAZ issues. Refer to appendix 8 for detailed instruction on how to perform these measurements.

1602. IMPORTANCE OF MEASUREMENTS . The importance of this function cannot be overemphasized.

The results of the FMO's measurements can affect the safety, health, and in extreme cases, the life of a person who shall work or be in the area being measured. The latest edition of ORDER 3900.19B SHALL BE UNDERSTOOD BY THE FMO AND STAFF. The order is very detailed in its description of the two basic kinds of radiation and the limits in which the human body can safely exist.

1603. FMO PARTICIPATION LIMITATION . Only measurements of level are made by the FMO.

1604. IMPORTANCE OF ACCURACY . The measurements made by the FMO are only as good as the calibration of the instrumentation used and the accuracy, thoroughness, and professionalism of the FMO or staff engineer making the measurements.

1605. INSTRUMENT CALIBRATION . The calibration of instrumentation is the responsibility of the FMO.

All instruments involved shall be calibrated at least annually, or more frequently if the manufacturer recommends.

In the case of ionized radiation instrumentation (Victoreen 440RF), the built-in calibrator will be used to verify approximate calibration immediately before any measurements of record are made. If the built-in calibrator leads to readings greater or less than 5 percent of the specified, the instrument will not be used for measurement until the manufacturer or a certified field calibration station has recalibrated it.

1606. AVAILABILITY . The instruments shall be available at all times, and in condition for immediate use.

This means all required batteries are fresh, and internal calibration checks have been made at periodic intervals.

When Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services, Program Office, or Flight Surgeon requests a measurement, the FMO response will be commensurate with the urgency of that request. Particularly in the case of a suspected case of employee, general public or visitor radiation, the Page 217 6050.32B Chapter 16 – continued 11/17/05 measurements shall be made as quickly as possible and the results given verbally to Technical Operations ATC Spectrum Engineering Services and Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services, even before the written report is completed. Technical Operations ATC Spectrum Engineering Services also shall be advised of results by email or fax.

1607. RAMIFICATIONS . The FMO is charged by directive to be the responsible person in the service area to make all nonroutine radiation hazard (RADHAZ) measurements. This is not a transferrable responsibility.

If the FMO cannot make the measurements for any reason, Technical Operations ATC Spectrum Engineering Services shall be contacted immediately for assistance .

a. Any measurement made as a result of a complaint by any person, FAA or not, of radiation injury from FAA equipment is likely to be used as a basis for liability assessment.

b. The person making the measurement may be required to appear as a Federal Government witness at an administrative hearing or trial litigation and may be required to prove expertise based on knowledge and experience in making measurements.

c. It is imperative that the FMO be thoroughly familiar with the equipment used. The FMO shall be knowledgeable of the manufacturer's specifications on accuracy, calibration requirements, and procedures for use and overall analysis procedures.

d. Except under extenuating circumstances , the FMO's RADHAZ equipment shall not be loaned outside the FMO office .

e. The FMO shall assure that all personnel who would use the instruments are thoroughly trained in the use of RADHAZ measurement equipment. The FAA will provide the necessary training. It is highly desirable that regular measurements on NAS equipment, e.g., long-range radars, be done as a proficiency-training requirement.

1608. MEASUREMENT PHILOSOPHY.

a. The FMO is not authorized to make any judgment as to any health hazard or lack thereof. When measurements have been completed, they shall be reported as required, followed by a written report signed by the person actually making the measurements.

b. Order 3900.19B specifies that the measurements will be made with the full cooperation and assistance of maintenance and management personnel responsible for the equipment concerned. It is likely that those persons will be watching as the measurements are being made, to see whether the indications might show a hazardous condition. The FMO should be fully open to those persons responsible who watch as to the numeric values obtained. But the FMO or engineer making the measurements shall make no assumptions as to health hazards pro or con. If pressed for comment, the FMO will refer the inquirer to Order 3900.19B, the service area Flight Surgeon or the ROSHM.

1609. MEASUREMENT CONSIDERATIONS .

a. Where a radar is rotating , it will be nearly impossible to receive an average power density level above the MPE. Considering the width of the radar beam and the antenna azimuth rate, a person at a fixed point (unless it was in the immediate vicinity of the radar antenna sail) would receive only that percentage of power equal to the beam width divided by 360, per unit time. For instance, a 2º beam width rotating radar would radiate any given point only 2/360 or 0.55 percent of the power measured at the same point under radar fixed illumination.

There is substantial radiation from the side lobes, but normally -30 dB or so down from the main lobe peak.

Page 218 11/17/05 Chapter 16 - continued 6050.32B b. In the near field , antenna lobes are not well defined and calculations based on them cannot be totally relied upon. This point is very significant and should be brought out in any report as a result of measurements of a rotating radar.

c. Use of a field strength meter for RADHAZ measurements shall be considered only when the level is less than 1 mW/cm . Greater levels may not be read accurately by the field strength meter due to the limit of the shielding of the field strength meter, or front end overload. In those cases where a field strength meter is used, the "peak hold" mode must be used so that the meter ballistics can be negated by the time hold. Conversion from dB/μv to mW/cm must be accomplished after the field strength meter measurement is completed. For this procedure, refer to the RFI manual described in paragraph 1400.

d. Persons uninformed about radiation may become overly concerned when they think they might be in a hazardous field. In this regard, the FMO shall never rely upon inexpensive non-ionized "radiation detectors" which can be bought for only a few dollars. Not only are they without any calibration, they usually are designed to operate on peak power, rather than average. About the only thing that can be said for them, other than they frighten people, is that they usually are very over-sensitive, so that persons using them probably are far safer than they think.

e. Home made detectors can be a problem. In one instance, an FAA radar site employee claimed radiation injury from the radar. The employee had constructed a standard Yagi antenna, resonant to the radar frequency, and placed a small NE-2 neon bulb at the feed point. The bulb lit nearly anywhere on the transmitter floor level, whenever the Yagi was pointed upward. Even considering the gain of the constructed Yagi, it took considerable time and effort to show that the bulb was lighting from peak power. Actual calibrated measurements throughout the area showed less than 5 percent of the MPE.

f. Diversity of opinion concerning radiation dangers must not in any way distract the FMO from absolutely assuring every reported or suspected radiation hazard is thoroughly investigated and reported as required in Order 3900.19B.

1610. MEASUREMENT STANDARDS AND PROCEDURES . Whether ionized or non-ionized, measurement of radiation is really just a form of field strength measurement, with which the FMO is very familiar in spectrum surveillance work. The difference is that in an area where possible health hazard from ionized radiation is being investigated, measurement shall be approached much more carefully than the usual field strength measurement.

a. Action levels are those employee exposure levels that trigger the implementation of Chapter 14 of Order 3900.19B and related program guidelines, administered by Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services. When these levels are exceeded, additional surveys may be requested and protective steps will be initiated by FAA Safety personnel to ensure worker safety.

b. The latest approved version of the MPE Standards for uncontrolled environments (at the time of this order, the 1999 Edition of IEEE/ANSI C95.1) shall be used as "action levels" for all environments where there is potential for exposure to non-ionizing radiation . If these standards are exceeded, further measurements may be requested by Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services to determine whether non-ionizing radiation levels exceed the ACGIH TLVs for controlled environments. The reference standard for ionizing radiation is provided by the most current version of the ACGIH TLVs.

c. All equipment used will have current calibration (e.g., less than one year since last calibration, or Page 219 6050.32B Chapter 16 – continued 11/17/05 whatever the manufacturer recommends).

d. Equipment batteries will be checked and verified as good, or replaced before measurement.

e. Persons making the measurements shall have sufficient experience in making such measurements and/or have completed the Academy RadHaz Course 44516, Radiation Hazard Theory and Measurement Procedures and Course 40606, Radiation Measurement Procedures Lab. If questions arise concerning procedures, refer to the above course materials.

f. The FMO surveyor shall not make any determination whether the noted value of radiation is "safe" or "unsafe." That is for medical personnel and industrial hygienists to determine. However, if measured radiation levels equal or exceed the non-ionizing or ionizing action levels, the appropriate management personnel of the facility being surveyed, the Regional Occupational Safety and Health Manager (ROSHM) or Safety Officer, and the Technical Operations ATC Spectrum Engineering Services shall be advised immediately of the level indicated. If appropriate, inside or outside areas should be marked off as easily recognizable as a "do not enter" area by the FMO.

g. When a measurement is completed , the FMO shall prepare a report and forward a copy to Technical Operations ATC Spectrum Engineering Services, Environmental, Energy Conservation, and Occupational Safety and Health (EEOSH) Services, the service area Operations Branch, and the System Management Office (SMO) regardless of the level of the radiation measured.

h. Automated functions to facilitate the calculation and reporting of radiation measurements are available to support the user, as highlighted in chapter 19, paragraph 1910.

1611. IONIZED RADIATION MEASUREMENT PROCEDURES .

a. Ionized radiation deals with those extremely short wavelengths in the x ray, alpha, beta and gamma ray bands. The instrument supplied to all FMOs, and the only approved instrument is the Victoreen 440RF (Version D). The "RF" portion of the model number indicates that it is shielded for operation in even very high RF fields.

Other instruments, especially the CDV-700, shall not be used without consulting Technical Operations ATC Spectrum Engineering Services. While it is accurate for radiation purposes, the CDV-700 is not accurate in the presence of high RF fields as may be encountered in FAA facilities.

b. Calibration and use .

(1) The very first action the measuring engineer shall take is to thoroughly read the instruction book that comes with each instrument. Complete familiarity with its provisions is mandatory before every measurement.

(2) Next, battery level shall be checked by the integral meter. If not at an operating level, batteries shall be replaced before the meter is used for measurement.

(3) Instrument self-calibration is accomplished by bringing the built-in calibration source into the specified area of the sensing cylinder. Measurements may proceed only if the self-calibration test is satisfactory.

(4) Turn on the instrument to its most sensitive level. The circuit should be zeroed, if necessary.

Zeroing should be checked at all scale levels.

(5) The meter should read nearly zero except for an occasional flick at the lowest scale level, caused by casual neutrons or gamma rays passing through the sensor. If the meter reads considerably upscale, the reason for that level reading shall be determined before any further readings are made. It is important that the instrument is Page 220 11/17/05 Chapter 16 - continued 6050.32B first turned on well outside any expected measurable radiation area.

(6) Once the meter is found to be operating normally , the area that is to be measured will be entered slowly and carefully. Watching the meter, the FMO shall carefully "sweep" the area under measurement, carefully noting and recording all readings above ambient zero level. The engineer accomplishes this by holding the instrument with its ion chamber facing the source to be measured. The instrument is slowly moved over the face of the cabinet or whatever container houses the suspected source. It shall be done slowly because the meter is damped and there is a short delay time before the meter reaches its extremity value, up or down.

(7) Most likely areas of radiation will be around windows or door jambs of high power klystron or magnetron tube cabinets, such as those found in TACANs and radars. Entire surfaces of cabinets, including the power supplies, should be systematically swept for readings. X rays are generated by a stream of electrons impinging upon a metal surface under the influence of high voltages, usually in excess of 20 kilovolts.

(8) During the sweep , the instrument shall be held well in front of the body, as it is moved toward or into the suspected field. To the extent possible, if less than MPE, put the sensor face as close to the device being measured as possible without touching it.

(9) Whenever a MPE is approached , the FMO will advance very slowly up to that limit. Should readings above the MPE be required, the instrument will be placed into those higher fields by means of a pole or other convenient device holding it, so the FMO is not subjected to levels above the MPE. At or above the MPE, the levels vs. distance in inches or feet from the radiating source are very important and should be measured and recorded for the report.

(10) Paragraph 1608 c. notwithstanding , if a level exceeding the MPE is found, the FMO shall advise the facility management, the Safety and Environmental Compliance Manager (SECM), and the ROSHM, even if after hours or a non-workday.

(11) Instrument calibration should be accomplished at least annually, or at any time its accuracy is questioned.

1612. NON-IONIZED RADIATION MEASUREMENT AND PROCEDURES . Non-ionized radiation refers to RF, even though it may be in the Extremely High Frequency (EHF) band, 30-300 GHz. Measurements of RF fields employ resonant loops (LF, MF, and HF), resonant dipoles (VHF and UHF), or isotropic probes for varied levels of high power in SHF and EHF. Measurements are made by field strength meters, calibrated in μ v/m, dB above 1 μv (dB μ v), or power density meters calibrated in mW/cm . Field strength meters are typically used for lower level fields. Good treatises on this measurement theory are available in standard electronic engineering handbooks.

a. The Narda power density meter is used for power levels of 1 mW/cm and greater. The instrument consists of a hand-held calibrated detector circuit with an integral meter. Two associated probes for two different ranges of power have been supplied. One or the other of the probes is used, connected by the supplied cable to the detector. The Narda is usually used in connection with measurement of a high power radar or close proximity measurements of TACAN. Other instruments that could be used are other field strength meters (e.g., Eaton NM- 65T, NM-67T, NM-37/57, Electrometrics Models EM-2135 (EMC-60), EM-2125 (EMC-30), EM-2110 (EMC- 11), spectrum analyzers (e.g., any of several HP or Tektronix, now used by FAA, or equivalent) with associated antennas, or other FAA approved instrument. Unless otherwise noted, the following direction pertains to the use of the Narda power density meter.

(1) First, the measuring engineer is to be thoroughly familiar with the instruction book for the instrument. Familiarity with operation procedures covered in the instruction book may be a matter of inquiry in Page 221 6050.32B Chapter 16 – continued 11/17/05 any court testimony that could be required.

Page 222 11/17/05 Chapter 16 - continued 6050.32B (2) The only calibration to be done is to check battery level and zero the instrument with appropriate probe attached. Proceed only if readings are normal. Note: The calibration/zero procedure is described in the instruction book. The probes need individual instrument insertion calibration for each use. The instruction book contains the procedure. Note that they are very delicate and shall not only be handled with care, but not subjected to levels in excess of their ratings.

(3) Once calibrated , the measurement procedure may begin. Using the highest power probe, approach the source to be measured. If it is the radiation from the antenna of a rotating radar, prior arrangements will have to have been made to get radar shutdown so that a steady-state radiation can be obtained for measurement.

(4) All radar types currently used by FAA have been measured previously and found well below MPE below the antenna sail. Therefore, initial measurements can be started in the radome or at the pedestal level, so long as the engineer's body does not extend into the plane of the sail area. However, if there is any doubt whatsoever, measurements should be started well below the sail level and gradually moved up into the general area.

(5) The probes are nondirectional , except that a signal coming from the direction of the handle would not be measured accurately.

(6) To use the instrument , hold the detector in one hand, the probe in the other. Start well outside the expected area of high radiation. Slowly move into the area and "sweep" the suspect area with the probe pointed toward the source. "Toward" means that the probe handle is pointed away from the source. If the source is radar, the radar antenna shall be stopped, and the measurement location searchlighted, if the main beam of the radar is being investigated for radiation level. Hold the probe over the head at a reasonable distance. Using an elevating device such as a "cherry picker," the FMO should slowly move up into the main beam with the probe, while watching the Narda meter. Move the probe through the highest level of indicated radiation, until the level starts dropping.

(7) Once the MPE is reached , further intrusion beyond will be by remote means only. The Narda is supplied with a calibrated cable that is intended for this purpose. Use an appropriate non-metallic pole and fashion a lashing or mount for the probe. Using it at the end of the pole, slowly position the probe into the "hot" area being measured. All levels vs. distance shall be accurately measured so that values of distance in feet and inches can be clearly shown on the report.

(8) If levels are found to be too low for the scale readings of the highest probe, the engineer should back off from the high density area, change and recalibrate with the lower power probe, then return to the area for measurement.

(9) For lower density devices , such as microwave ovens or microwave links, the process will be essentially the same, except the expected power levels will be so low that poles and other "remote reading" assisting devices will not be needed. If the level is below 1 mW/cm , then a field strength meter may be required, with appropriate antenna. Nonetheless, prudence shall be exercised in approaching the source to be measured.

(a) If a microwave dish is the source , the probe can be slowly swept all over the face of the dish, even into the area of the feed horn. Since the average power is being measured from a pulsed source, the probe and associated equipment need a little time to come up to the correct reading. CAUTION: The probe surface must never touch any solid part of a device being measured. In some models, the contact can create an instantaneous static discharge that can destroy the delicate probe.

Page 223 6050.32B Chapter 16 – continued 11/17/05 (b) If a microwave oven or similar device is the source, the probe should be swept over the entire cabinet, with particular attention being given to the edges of the door, glass windows and vents. Again, it is imperative that the probe not touch the source.

(10) Guidance for the distance vs. power density and MPE in the main beam for the various radars now being used by FAA is found in Order 3900.19B. A chart of current conditions is provided in figure 16-2.

b. The field strength meter will be used for lower level measurement areas. The operation of the meters will be in the normal field strength measurement mode and procedure. Since the upper measurement limit of these instruments is well below the "safe" level, use normally will be at considerable distances from any high power source. Since they are capable of being operated on their internal batteries, they are amenable to use in portable conditions.

See also paragraph 1609, (1) (b).

Page 224 11/17/05 Chapter 16 - continued 6050.32B FIGURE 16-2. RADARS USED BY FAA WITH POWER DENSITIES >MPE Transmitter Power Nominal Radar Peak Average Frequency MPE Distance# Type MW W MHz mW/cm Ft AN/FPS-20 2.0 4319 1300 4.3 315 AN/FPS-60 (simplex) 2.0 4319 1300 4.3 315 AN/FPS-60 (duplex) 2.0 8638 1300 4.3 630 AN/FPS-6/90 2.8 2040 2800 9.3 264 ASDE 0.0045 3 15,950 10.0 * ASR-4,-5,-6. 0.425 403 2800 9.3 29 ASR-7 (AN/GPN12) 0.5 475 2800 9.3 37 ASR-8 (AN/GPN-20/27) 1.4 875 2800 9.3 92 (Simplex) ASR-8 (AN/GPN-20/27) 1.4 1750 2800 9.3 172 (Diplex) ASR-9 1.237 1430 2800 9.3 205 ASR-11 .0229 324 2840 9.5 90 ARSR-1,-2 5.0 3595 1315 4.4 295 ARSR-3 (simplex) 4.6 3140 1315 4.4 230 ARSR-3 (duplex) 4.6 6280 1315 4.4 460 ARSR-4 0.93 558 1315 4.4 260 NEXRAD (WSR-88) 1.0 2000 2850 9.5 172 TDWR 0.31 550 5625 10.0 354 * MPE not exceeded.

# Calculated distance from antenna to point on main beam axis where power density equals the MPE.

Page 225 6050.32B Chapter 16 – continued 11/17/05 1613. MEASUREMENT CONSIDERATIONS AND REFERENCE DATA.

a. Radiation measurements below 100 MHz will normally be for a Non-Directional Beacon (NDB) and Compass Locator (COMLO) in the 190-535 kiloHertz (kHz) band, NRCS (See Chapter 7) High Frequency (HF) in the 2-28 MHz band or 75 MHz Marker transmitters. The NRCS HF is Single Sideband (SSB) Suppressed Carrier emission, so measurements must be taken with the transmitter being modulated by a constant tone source to stabilize the SSB radiation, set at what is considered 100 percent power output. In cases of frequencies between 0.1 - 100 MHz, both the electric (E) field and the magnetic (H) field values shall be obtained by measurement. This is to assure compliance in both fields.

The power density (PD) (also S) value in mW/cm is then calculated by using the formulas: 2 2 2 2 E Field: PD = E /3770 H Field: PD = H x 37.7 mW/cm mW/cm b. Radiation measurements taken in the Very High Frequency (VHF) and Ultra High Frequency (UHF ) A/G bands shall be done with tone modulation at 100 percent to assure worst case condition.

c. Radiation measurements taken of Distance Measuring Equipment (DME) and TACAN as a pulsed emission requires the measurement to be taken in peak values, then corrected for average values by introducing the duty cycle (DC) factor. For the worst case, the DC is 0.04. Therefore, after the peak reading is obtained, multiply it by 0.04 to get the average power. Only the E field is required.

d. Radiation measurements for rotating Airport Surveillance Radar (ASR), Air Route Surveillance Radar (ARSR), Airport Surface Detection Equipment (ASDE), Terminal Doppler Weather Radar (TDWR) and Next Generation Weather Radar (NEXRAD) radars have additional factors to be considered: (a.) the DC, obtained by multiplying the pulse width (PW) (in seconds) times the pulse repetition rate (PRR) in pulses per second (pps); (b.) the Fractional Exposure Time (FET) obtained by dividing the antenna beam width (BW) which is 4 degrees by 360. Thus, FET= 4/360= 0.011.

(a) For rotating radar, only the peak E fields, usually in Volts per meter (V/m), need to be measured.

The Power Density (S) = (E /3770) x DC x FET (using the peak E field value).

(b) For radar with antenna stationary and directly pointed at the point of measurement (searchlighting), only the DC factor is used to determine average power from the measured peak power.

e. The electromagnetic MPEs for uncontrolled environments from the 1999 Edition of ANSI/IEEE Standard C95.1 are presented in figure 16-3. It is important to use the most current version of the standard that is available at the time of the survey. The Uncontrolled MPEs shall be used as action levels for all environments where there is a potential for exposure to non-ionizing radiation.

f. The electromagnetic MPEs for controlled environments are presented in figure 16-4.

g. Figure 16-5 contains the 2001 ACGIH Ionizing Radiation TLVs. These guidelines are updated yearly. It is important to use the most current version of the standards that is available at the time of the survey.

Page 226 11/17/05 Chapter 16 - continued 6050.32B FIGURE 16-3. NON-IONIZING MPE - UNCONTROLLED ENVIRONMENT MAXIMUM PERMISSIBLE EXPOSURE FOR UNCONTROLLED ENVIRONMENTS Electromagnetic fields* Frequency Range Electric Magnetic field Power Density (S) Averaging Time 2 2 (MHz) field Field Strength E-Field, H-Field |E| , S or |H| Strength (H) (A/m) (mW/cm ) (Minutes) (E) (V/m) 1 2 3 4 5 # 0.003 – 0.1 614 163 (100,1000000) 6 6 2 # 0.1 – 1.34 614 16.3/f (1000, 10000/f ) 6 6 2 2 2 1.34 – 3.0 823.8/f 16.3/f (180/f , 10000/f ) f / 0.3 6 2 2 3.0 – 30 823.8/f 16.3/f (180f , 10000/f ) 30 6 1.668 3.336 1.337 30 – 100 27.5 158.3/f (0.2940000/f ) 30 0.0636f 100 – 300 27.5 0.0729 0.2 30 30 300 – 3000 - - f/1500 30 3000 – 15000 - - f/1500 90000/f 1.2 15000 – 300000 10 616000/f Note-f is the frequency in MHz * The exposure values in terms of electric and magnetic field strengths are the values obtained by spatially averaging values over an area equivalent to the vertical cross section of the human body (projected area).

# These plane-wave equivalent power density values, although not appropriate for near-field conditions, are commonly used as a convenient comparison with MPEs at higher frequency and are displayed on some instruments in use.

Page 227 6050.32B Chapter 16 – continued 11/17/05 FIGURE 16-4. NON-IONIZING MPE – CONTROLLED ENVIRONMENT MAXIMUM PERMISSIBLE EXPOSURE FOR CONTROLLED ENVIRONMENTS Electromagnetic fields* Frequency Electric field Magnetic Field Power Density (S) Averaging Time 2 2 Range Strength (E) Strength (H) E-Field, H-Field |E| , |H| , or S (MHz) (V/m) (A/m) (mW/cm ) (Minutes) 1 2 3 4 5 # 0.003 – 0.1 614 163 (100,1000000) 6 2 # 0.1 – 3.0 614 16.3/f (1000, 10000/f ) 6 2 2 3.0 – 30 1842/f 16.3/f (900f , 10000/f ) 6 30 – 100 61.4 16.3/f (1.0, 10000/f ) 6 100 – 300 61.4 0.163 1.0 6 300 – 3000 - - f/300 6 3000 – 15000 - - 10 6 1.2 15000 – 300000 - - 10 616000/f Note-f is the frequency in MHz * The exposure values in terms of electric and magnetic field strengths are the values obtained by spatially averaging values over an area equivalent to the vertical cross section of the human body (projected area).

# These plane-wave equivalent power density values, although not appropriate for near-field conditions, are commonly used as a convenient comparison with MPEs at higher frequency and are displayed on some instruments in use.

Page 228 11/17/05 Chapter 16 - continued 6050.32B FIGURE 16-5. IONIZING TLV .

TYPE OF EXPOSURE ANNUAL DOSE LIMIT Effective Dose a) in any single year 50 mSv (millisievert) * ( See Note 1 ) b) averaged over 5 years 20 mSv per year Annual Equivalent Dose to: a) lens of the eye 150 mSv b) skin 500 mSv c) hands and feet 500 mSv Embryo-Fetus exposures once the pregnancy is known • Monthly equivalent dose # 0.5 mSv ( See Note 2 ) • Dose to the surface of women ’ s 2 mSv for the re- abdomen (lower trunk) mainder of the pregnancy • Intake of radionuclide 1/20 of Annual Limit on Intake (ALI) Radon Daughters 4 Working Level Months (WLM) # Sum of internal and external exposure but excluding doses from natural sources as recommended in National Council on Radiation Protection and Measurements (NCRP) * Conversion factors: 10 mSv = 1 Rem = 1000 mR.

1 mSv = 100 mR Note 1: Action level any single year Note 2: Action level for pregnant women 50 mSv = 5000 mR 0.5 mSv = 50 mR Action level = 5000 mR/yr or 2080 hrs/yr Action level = 50 mR/mo or 60 hrs/mo Action level = 2.4 mR/hr (approximately) Action level = 0.3125 mR/hr These action levels are cumulative maximums over a standard work-hour/year of 2080 hours and a standard work-hour/month of 160 hours.

Page 229 6050.32B Chapter 16 – continued 11/17/05 FIGURE 16-6a. LETTER OF AGREEMENT SAFTEY PROGRAM RESPONSIBILITIES Letter of Agreement for Division of Functional Radiation Safety Program Responsibilities Between Technical Operations ATC Spectrum Engineering Services and Technical Operations ATC Facilities In September 2002, the former Federal Aviation Administration (FAA) organizations, the Resources Management Program, and the Spectrum Policy and Management Program, signed a letter of agreement (LOA) dividing the Radiation Safety Program (RSP) responsibilities that were assigned to the former FAA organization, the Airway Facilities Service, by Chapter 14 of FAA Order 3900.19B: FAA Occupational Safety and Health Program. This LOA replaces the 2002 LOA and highlights the present FAA organizations responsible for the various duties under the RSP. Specifically, it clarifies the duties assigned to Technical Operations ATC Facilities and Technical Operations ATC Spectrum Engineering Services.

Technical Operations ATC Facilities shall: 1. Appoint a Radiation Protection Officer to serve as the Agency focal point for all employee radiation health and safety issues.

2. Serve as the budget advocate for funds to carry out assigned Technical Operations ATC Facilities RSP duties.

3. Perform FAA employee exposure assessments.

4. Perform induced current measurements, dosimetry, measurements of low frequency non-ionizing sources, and other measurements as necessary, that are not performed by Technical Operations ATC Spectrum Engineering Services as established in FAA Order 6050.32, Spectrum Management Regulations and Procedures Manual. These surveys are required to assess employee exposure at FAA communication, navigation and surveillance (CNS) facilities.

5. Perform routine ionizing and non-ionizing radiation surveys to assess FAA employee exposure at CNS facilities.

6. Provide technical assistance to regions in radiation risk management, exposure assessment, and dosimetry as required.

Page 230 11/17/05 Chapter 16 - continued 6050.32B FIGURE 16-6b. LETTER OF AGREEMENT SAFETY PROGRAM RESPONSIBILITIES 7. Assist the Office of Environment and Energy (AEE) as co-liaison in coordinating with organizations external to the FAA such as the Occupational Safety and Health Administration (OSHA), National Institute of Occupational Safety and Health (NIOSH), American Conference of Governmental Industrial Hygienists (ACGIH), and the Environmental Protection Agency (EPA), on radiation health and safety issues.

8. Provide assistance to Technical Operations Services organizations to ensure that FAA Maintenance Orders in the 6000 Directives Series and related publications incorporate radiation risk management practices and current FAA radiation protection policies.

9. Ensure that annual field safety assessments of employee work tasks and environments are conducted to identify employees for inclusion in the RSP. Identify new operations, maintenance activities, and modifications to the work environment that may increase the potential for radiation exposure.

10. Implement initial and periodic radiation hazard evaluation training for safety and health professionals and staff. Implement safety awareness training for employees who work in environments where there is the potential for exposure at or above adopted FAA standards. Document all training and maintain all training records for the period required by OSHA.

11. Coordinate with the Office of Aviation Medicine (AAM) when seeking additional health or medical interpretation of any radiation measurement data.

12. Assist AAM to ensure that all exposure records, dosimetry measurement records, and related health and medical records are maintained in accordance with OSHA requirements.

13. Ensure that citizens and FAA employees have access to radiation survey, investigation, and exposure assessment data.

14. Coordinate with Technical Operations ATC Spectrum Engineering Services to obtain radiation hazard measurements on CNS systems in response to employee or union re q uests.

Page 231 6050.32B Chapter 16 – continued 11/17/05 FIGURE 16-6c. LETTER OF AGREEMENT SAFETY PROGRAM RESPONSIBILITIES 15. Provide internal coordination within the FAA on matters relating to radiation exposure assessment.

16. Serve as the point of contact for employee questions related to radiation hazards from equipment that is not part of the FAA's CNS facilities (e.g. microwave ovens, video display terminals, etc.)

17. Develop and provide informational resources on radiation safety to employees upon request.

Technical Operations ATC Spectrum Engineering Services shall: 1. Serve as budget advocate for funds to carry out assigned Technical Operations ATC Spectrum Engineering Services duties.

2. Serve as the focal point for performing ionizing and non-ionizing radiation hazard measurements during the baselining, or commissioning of FAA CNS facilities, or as otherwise required by Order 6050.32, Spectrum Management Regulations and Procedures Manual. Radiation hazard measurements will also be performed in response to employee requests. Written copies of all radiation measurements reports will be provided to Technical Operations ATC Facilities, Environmental, Energy Conservation, and Occupational Safety and Health Services, and the Regional Occupational Safety and Health Managers (ROSHM).

3. If a transmission tube (thyratron, klystron, magnetron, or amplitron) is found to emit radiation above the action level during a Radiation Survey (RS), the following information shall be added to the RS report: tube manufacturer, model, and serial number and current tube operating voltage.

4. Provide technical assistance to the service areas for radiation hazard measurements, defining radiation hazard environments, and radiation survey equipment calibration and maintenance.

Page 232 6050.32B Chapter 16 - continued 11/17/05 FIGURE 16-6d. LETTER OF AGREEMENT SAFETY PROGRAM RESPONSIBILITIES 5. Maintain an inventory of Frequency Management Officers' (FMO) radiation hazard measurement equipment that is updated annually. Ensure that radiation survey equipment is calibrated in accordance with manufacturer recommendations.

6. Coordinate with Technical Operations ATC Facilities and organizations external to the FAA such as Interdepartmental Radio Advisory committee (IRAC), Department of Defense (DOD), and the Federal Communications Commission (FCC) on spectrum issues relating to radiation hazards.

7. Periodically update FAA Order 6050.32, spectrum Management Regulations and Procedures Manual, and radiation hazard measurement training to ensure compliance with current radiation standards and policy.

8. Provide the FAA's spectrum engineering staff initial and periodic training in conducting ionizing and non- ionizing radiation hazard measurements of CNS facilities.

9. Make radiation measurement data available to citizens, employees, and FAA service area and headquarters staff.

10. Perform radiation hazard measurements in response to inquiries from other Federal agencies, Congressional Offices, citizens, and other external parties.

Signed by Signed by Jerrold B. Sandors Jack Nager for Oscar Alvarez Director, ATC Facilities Acting Director, ATC Spectrum ATC Facilities Engineering Services Date: 7/29/05 Date: 7/27/05 1614. thru 1699. RESERVED.

Page 232 (thru 234)

11/17/05 6050.32B CHAPTER 17. LAND MOBILE AND OTHER FM COMMUNICATIONS SYSTEMS FREQUENCY ENGINEERING 1700. GENERAL . This chapter will present guidance and criteria for engineering frequencies for FAA land mobile and other FM communications systems operating in the Federal Government fixed/mobile bands.

1701. FREQUENCY ENGINEERING . The FAA currently uses the bands 162-174 MHz and 406.1-420 MHz for land communications. For a description of how to perform a detailed engineering analysis, refer to the NTIA Manual, annex I.

a. While no formal criteria for cochannel and adjacent channel separation exist within FAA, separate cochannel assignments by 100 nmi or RLOS, where possible. For data links, use the same rule unless unique digital coding is available, such as in the Medium Intensity Approach Lighting System with Runway Alignment Indicator Lights (MALSR). In this case, close separation (down to 5 nmi) has been found to work satisfactorily.

b. No first adjacent channel (12.5 kHz) protection standard is provided for fixed/land mobile communications systems.

1702. SYSTEMS BASICS . FAA FM radio communications systems operating in the land mobile bands are of two major types: repeater/base/portable/mobile voice systems, and voice/data links.

a. The repeater/base/portable/mobile systems are voice systems used in support of the National Radio Communications Systems (NRCS), known internally as Command and Control Communications (C3).

b. The voice/data links are used for Low Level Wind Shear Alert System (LLWAS), MALSR, Remote Maintenance Monitoring (RMM), Automated Weather Observing System (AWOS), Stand Alone Weather System (SAWS) and other systems that require low capacity fixed RF links.

1703. C3/NRCS. The C3/NRCS VHF FM COMM frequency plan is as shown in figure 17-1.

FIGURE 17-1. C3/NRCS COMMUNICATIONS FREQUENCY PLAN Repeater Repeater Channel Uplink (MHz) Downlink (MHz) 1 169.325 172.925 2 169.350 172.950 3 169.375 172.975 4 169.250 172.850 5 169.275 172.875 6 169.225 172.825 7 172.1250 simplex 8 172.7375 simplex (except Alaska) 9 172.1750 simplex 10 166.1750 simplex Page 235 6050.32B Chapter 17 – continued 11/17/05 a. The NRCS VHF FM system is a three-way voice system. It can be used either through a repeater (duplex) or unit-to-unit (simplex.) See figure 17-2.

FIGURE 17-2. EXAMPLE OF A REPEATER/BASE/PORTABLE/MOBILE FM SYSTEM b. Using the repeater , any base, mobile, portable or hand-held unit may communicate with any other unit within RLOS range of the repeater by utilizing duplex operation. This consists of transmitting on one frequency (uplink) which is automatically repeated on another frequency. This second frequency (downlink) is then transmitted by the repeater and received by the intended unit and all others tuned to the same frequency.

c. Talkaround allows unit to unit direct communications without using the repeater. It is defined as simplex operation, where both units within RLOS transmit and receive on a single frequency, in this case the repeater output frequency (downlink). This permits short range communications without activating the repeater while permitting reception of the repeater at any time the units are not engaged in simplex communications (standby).

d. Tone activated squelch (PL). The PL acronym comes from the trade name of the first tone-activated squelch system (Motorola's Private Line). PLs are transmitted single tones between 67.0-254.1 Hz (42 total), but they are normally not heard in a commercial FM land mobile system due to the 300-3000 Hz system voice band pass filters built into the equipment. This is intentional, to permit use of control tones without interfering with the voice communications on the same units. They are continuously transmitted when the transmitter is keyed. Upon reception, the tones will open a matching PL squelched receiver, if PL is activated. If PL is activated on a receiver, only stations transmitting the same PL can be heard. The normal PL for the current analog NRCS radios is 136.5 Hz. In a few areas, a second PL may be used.

Page 236 11/17/05 Chapter 17 - continued 6050.32B 1704. RF VOICE/DATA LINK SYSTEMS .

a. LLWAS radio links are used to relay wind speed/direction information from field sensors to a central processor. LLWAS frequency requirements are satisfied within 406.1-420.0 MHz band. Frequencies for LLWAS equipment shall be selected from the following (MHz): 409.1750 410.3000 412.5375 413.5875 414.7875 418.1750 b. MALSR radio links are used to control approach lighting from the ATCT when it is not practical to use land lines. The frequency 165.7625 MHz shall be the primary channel for MALSR.

c. RMM radio links are used to relay maintenance and control data from a remote site back to a central monitoring point. Frequencies shall be selected from the following (MHz): 408.8250 410.0250 412.9375 412.9875 413.0125 413.0625 413.6000 417.8250 419.0250 If these specific frequencies are not available, system frequencies should be engineered in accordance with the NTIA Manual supplement for the 406.1-420.0 MHz band.

d. AWOS radio links are used to relay weather information from field sensors to a central processor. These links will be operated within the 406.1-420 MHz band on a case-by-case basis.

e. SAWS radio links are simplex operating systems used to relay weather data from a remote site to a master station. The frequencies 413.1125 MHz and 414.0125 MHz shall be the primary channels for this facility.

1705. MISCELLANEOUS RADIO LINKS. Low capacity RF links may be operated in the band 406.1-420.0 MHz on a case-by-case basis.

Page 237 6050.32B Chapter 17 – continued 11/17/05 1706. NARROW BAND REQUIREMENTS. Narrow band transmitter and receiver standards are presented in the NTIA Manual, Chapter 5.3.5.2. The narrow band standards support a 12.5 kHz channel plan, versus the previous 25 kHz channel plan. As of January 1, 2005, all systems implemented in the 162-174 MHz band must meet these standards. All new systems, and after January 1, 2008, all systems implemented in the 406.100- 420.000 MHz band must also meet these standards. The following parameters will be affected: Transmitter: Necessary bandwidth Unwanted emissions Frequency deviation Frequency tolerance* Receiver Necessary bandwidth Spurious response attenuation Adjacent channel selectivity Intermodulation rejection Conducted spurious emissions Frequency tolerance* *NTIA Manual Section 5.2 1707. thru 1799. RESERVED.

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11/17/05 6050.32B CHAPTER 18. ELECTRONIC ATTACK (EA) EVALUATIONS 1800. PURPOSE .

a. Most RFI experienced by FAA facilities is of an uncontrollable and unexpected nature. Indeed, in many instances, such RFI is unintended by the operator causing it. In many instances, FAA systems have methods of filtering out this RFI. However, there is one type of RFI which is intended and which the FAA usually has the ability to schedule, relocate or cancel. That type of RFI consists of EA military operations. Unfortunately, EA is sometimes conducted without prior coordination by the military. In this case, the problem has to be handled just as any unexpected RFI.

b. EA missions are military operations where electromagnetic signals are radiated intentionally or chaff is dropped to cause RFI to other military units. These missions are conducted on various portions of the spectrum.

These radiations can cause severe RFI to FAA facilities, particularly GPS, TACAN and radar. While training in electronic attack and dropping chaff is deemed necessary by the military to keep air crews combat-ready, it can also present a serious hazard to air safety. FAA must carefully review requests for this type of activity. FAA policy on EA activity is summarized below: (1) The Technical Operations Services technical analysis performed by the applicable service area or by Technical Operations ATC Spectrum Engineering Services evaluates the potential for NAS degradation. If the proposed EA mission degrades the NAS, FAA will not concur with the operation. To accommodate DOD EA training requirements, FAA will evaluate the possibility of NOTAMing affected facilities out to service (OTS) during specific mutually agreed upon times, on a case-by-case basis.

(2) The affected ARTCC or other designated FAA facility has final authority, based on current air traffic capacity, safety, weather or other valid reason, to allow an EA mission to proceed as scheduled or to refuse concurrence. However, if such refusal occurs after previous national authorization of a military EA activity, then the affected ARTCC or facility shall report such refusal through RFI or MCC reporting channels back to national authorities.

(3) Technical Operations ATC Spectrum Engineering Services forwards the coordinated FAA response after the technical Technical Operations Services analysis and coordination with the appropriate air traffic organization. Technical Operations ATC Spectrum Engineering Services also passes on or assigns an administrative EA control number to authorized operations. The military unit will refer to this control number when contacting the ARTCC for final approval to dispense chaff or to conduct other EA activity.

(4) Technical Operations ATC Spectrum Engineering Services will evaluate all EA requests which could impact GPS operations (e.g., 1164-1215 MHz and 1559-1610 MHz) and all Joint Tactical Information Distribution System (JTIDS) operations outside the limits set by the DOT/DOD Memorandum of Agreement (MOA) “Civil Use of GPS” (1993) Annex 3 (1999). JTIDS assignments covered by the MOA will be addressed through the frequency assignment process.

1801. DEFINITIONS.

a. A Military Operating Area (MOA) is the established airspace outside positive control areas to separate/segregate certain nonhazardous military activities from IFR traffic and to identify for VFR traffic where these activities are conducted.

Page 241 6050.32B Chapter 18 – continued 11/17/05 b. A Restricted Area is airspace designated under FAR Part 73 within which the flight of the aircraft, while not wholly prohibited, is subject to restriction. Restricted areas are designated when determined necessary to confine or segregate activities considered to be a danger to nonparticipating aircraft.

c. A Warning Area is airspace of defined dimensions over international waters that contain activity that may be hazardous to nonparticipating aircraft.

d. "Stop Buzzer/Chaff" or "Cease Buzzer/Chaff" are terms normally transmitted over "guard" channels (121.5 MHz and 243.0 MHz) which directs any military unit to stop electronic attack or to stop dropping chaff, as appropriate. It is important to realize that because of its slow fall rate and unpredictable winds, chaff may take several hours to reach the ground, with uncontrollable RFI occurring until the chaff is at ground level.

1802. APPLICABLE REGULATIONS AND DOCUMENTS .

a. Order 7610.11A, Coordinating Electric Attack Mission Requests , establishes internal FAA coordination procedures. It states that FMOs will coordinate with their respective service area air traffic organizations when reviewing EA proposals and establishes Technical Operations ATC Spectrum Engineering Services as the focal point for sending out the authorization to the military for EA operations after service area analysis is completed.

b. Order 7610.4, Special Military Operations describes general guidelines for military units for requesting and performing EA operations.

c. Order 7400.2, Procedures for Handling Airspace Matters, is primarily used by military units when they need to establish new special use airspace. It states that desired EA operations shall be considered during the planning stages of expanding or establishing new special use airspace.

d. DOD Chairman of the Joint Chiefs Staff Manual (CJCSM 3212.02A, Performing Electronic Attack in the United States and Canada for Tests, Training and Exercises) details EA approval procedures for use by the military services. The military instruction is coordinated with FAA to ensure that these procedures are adequate to protect critical safety communications, navigation and surveillance systems from interference. Figure 18-3 indicates those frequency bands, designated as "National" coordination with a superscript "1," which shall be coordinated and approved by the FAA prior to beginning EA operations. Paragraphs 1806-1808 of this order were extracted from Appendix I of the CJCSM.

e. DOT/DOD Memorandum of Agreement “Civil Use of GPS” (1993) Annex 3 (1999). The 1993 MOA is a broad overarching agreement delineating DOT and DOD responsibilities regarding civil use of GPS as DOD developed and implemented GPS. The Annex 3 implements the actual coordination activities between DOT and DOD to: facilitate coordination to ensure DOD can develop, test, exercise, and train necessary capabilities “without unduly disrupting or degrading civilian uses” as governed by the 1996 Presidential Decision Directive; facilitate timely reporting and resolution of GPs interference; specify jointly acceptable GPS interference analysis tools; and designate Technical Operations ATC Spectrum Engineering Services as the DOT point of contact.

DOD is required to submit test requests 60 days prior to the test, and the FAA has 30 days to respond. Annex 3 establishes the organizational responsibilities for GPS interference.

1803. RESPONSIBILITIES .

a. Technical Operations ATC Spectrum Engineering Services shall : (1) Establish guidance to ensure consistency for authorizing EA activity throughout the service areas.

Page 242 11/17/05 Chapter 18 - continued 6050.32B (2) Provide the written, consolidated FAA response and authorization to military EA requests based on FMO analysis and coordination. This response may be transmitted via email, fax or message, depending upon the request.

(3) Assign an administrative EA control number for reference, if required. Normally, the submitting military agency assigns a control number to the proposed activity. If this does not occur, then the FAA assigns this number. Such a control number will include a designator indicating the requesting agency, a representation of the fiscal year in which the request is made, and a unique control number. An example of this would be ACC 02-04, where ACC refers to the U.S. Air Force Air Combat Command, 02 refers to FY 2002, and 04 is a number uniquely assigned to this request. To continue this example, NSAWC 02-04 would refer to the fourth test sponsored by the Naval Strike Warfare Center in FY 2002.

b. Service area FMOs shall : (1) Coordinate with their service area air traffic organizations and applicable FAA ARTCCs and facilities as needed to determine whether FAA facilities could be impacted by the proposed EA mission.

(2) Perform a thorough analysis of the proposed EA impact on FAA systems within their service area.

(3) Provide a written NAS facilities EA impact analysis to Technical Operations ATC Spectrum Engineering Services for the proposed EA along with any recommendations for restrictions; e.g., altitude, time of day, prohibited frequencies, etc.

1804. ANALYSIS OF EA REQUEST .

a. The following general policy outlines the minimum analysis required when evaluating EA proposals.

(1) FAA does not allow its systems to experience RFI intentionally because of the possibility of degradation of safety of flight.

(a) Military entities are requested to accept restrictions that will allow EA training without RFI to FAA systems.

(b) In those cases where FAA allows RFI in order to accommodate military training, affected facilities or Centers will NOTAM the systems OTS, where necessary.

(2) FAA does not allow EA training on 1030 MHz, 1090 MHz, 108-137 MHz, 960-1240 MHz, 1559-1610 MHz or 5030-5090 MHz except under highly restrictive and limited instances.

(3) There are certain frequency bands that require special consideration because they are used by civil aviation for critical aeronautical radionavigation operations. However, the FAA does not centrally manage them.

For example, these bands include 4200-4400 MHz (radar altimeter) and 13.25-13.40 GHz (airborne weather radar). Active EA operations are seldom performed in these bands, but chaff can impact these airborne systems.

Care will be taken that chaff operations are not allowed near air routes so that such airborne systems do not receive interference.

b. The following general procedures will be used in evaluating EA electronic jamming proposals.

(1) Determine whether the electronic jamming is to be done in a frequency band in which FAA supports air traffic services. FAA evaluates only those jamming operations that could cause RFI to FAA operations.

Page 243 6050.32B Chapter 18 – continued 11/17/05 (2) Determine whether the jamming is to be done in an area within RLOS of facilities supporting the National Airspace System and in a frequency band of concern to the FAA. Note : consider terrain shielding, if applicable.

(3) Determine whether the power level will be sufficient to cause RFI to FAA facilities if the jamming is to be within RLOS.

(4) Determine possible restrictions (e.g., altitude limitations, possible use of spot frequencies rather than bands, etc.) which could be imposed to allow the jamming.

c. The following general guidelines shall be followed when evaluating EA chaff proposals: (1) Only consider the primary and "second time around" targets when evaluating chaff. Experience has shown that "third (or higher) time around" targets are not detected by FAA radars.

(2) Chaff normally interferes with radar . However, there is a small possibility that it could cause RFI to microwave systems such as RCL if dropped within 500 feet of the microwave beam.

(3) Determine whether the chaff is designed to affect a frequency band in which FAA has radar or microwave facilities.

(4) If the chaff is designed to affect a frequency of interest to FAA, determine whether it is to be within RLOS. Note : terrain shielding may be considered in this evaluation. See (1) above regarding "second time around."

1805. CONCLUSIONS . Analysis of EA operations, both electronic jamming and chaff, is complicated and requires good engineering practices. FAA is committed under Title 49. U.S.C., to provide a safe and efficient NAS. This Act also requires the FAA to make every effort to accommodate necessary military EA training. By careful analysis and proper procedures, FAA can permit most military EA training without impacting aeronautical safety.

1806. OPERATIONAL BAND AND CHANNEL CODES. The following bands and channels are set up to give one standard system of frequency band designations for EA operations and to facilitate the operational control of EA. The bands are identified in alphabetical sequence. Each band is divided into 10 numerical channels. The phonetic alphabet and numerical channel numbers are used to identify the EW frequency. During operations, when it becomes necessary to identify an exact frequency, the frequency is specified as a numerical designation (lowest frequency in any channel) plus frequency in MHz above the base frequency. Example for 1315 MHz: DELTA 4 covers the frequency range 1,300-1,400 MHz; 1,315 MHz would therefore be designated DELTA 4 plus 15. See Figure 18-1.

Page 244 11/17/05 Chapter 18 - continued 6050.32B FIGURE 18-1. FREQUENCY BAND DESIGNATIONS Band Frequency (MHz) Channel Width (MHz) A(lpha) 0 – 250 25 B(ravo) 250 – 500 25 C(harlie) 500 - 1,000 50 D(elta) 1,000 - 2,000 100 E(cho) 2,000 - 3,000 100 F(oxtrot) 3,000 - 4,000 100 G(olf) 4,000 - 6,000 200 H(otel) 6,000 - 8,000 200 I(ndia) 8,000 - 10,000 200 J(uliet) 10,000 - 20,000 1,000 K(ilo) 20,000 - 40,000 2,000 L(ima) 40,000 - 60,000 2,000 M(ike) 60,000 - 100,000 4,000 N(ovember) 100,000 - 200,000 10,000 O(scar) 200,000 - 300,000 10,000 Page 245 6050.32B Chapter 18 – continued 11/17/05 1807. FREQUENCY BAND CORRELATION. Figure 18-2 depicts the correlation between previous frequency band designations (sometimes used by ARTCCs) and band designators defined in this chapter.

FIGURE 18-2. FREQUENCY BAND CORRELATION Frequency Range EW Frequency Band * Radar Design Frequency Band 0-250 MHz A HF/VHF 250-500 MHz B UHF 500-1,000 MHz C UHF 1-2 GHz D L 2-3 GHz E S 3-4 GHz F S 4-6 GHz G C 6-8 GHz H C 8-10 GHz I X (8-12.5 GHz) 10-20 GHz J Ku (12.5-18 GHz) 20-40 GHz K K (18-26.5 GHz) 40-60 GHz L Ka (26.5-40 GHz) 60-100 GHz M 40-100 Millimeter 100-200 GHz N Sub-millimeter 200-300 GHz O Sub-millimeter * Band designations sometimes used by ARTCC 1808. EA COORDINATION REQUIREMENTS BY FREQUENCY BAND.

a. Canada: All EA performed in Canada requires national coordination.

b. United States: Figure 18-3 has been coordinated at the national level. The status of the frequency bands for EW in the United States is annotated below as “Local,” “Local (FCC),” or “National.” Each status is defined in the Glossary of this manual and in the procedures in Enclosure C.

c. National Coordination: In Figure 18-3, “National” coordination requires that the request be forwarded to the cognizant Military Department (MILDEP) FMO for coordination. The frequency bands are listed consecutively to include all frequencies for ease of understanding. Obviously, one frequency cannot be both national and local. Therefore, the following rules apply. All frequency bands designated national are inclusive.

All “Local” or “Local (FCC)” frequencies adjacent to a national frequency band begin or end at the first increment adjacent to the national frequencies. Local (FCC) frequencies are inclusive when adjacent to a local frequency. For example, in the band 25-50 MHz, all frequencies from 25 MHz through 50 MHz require national coordination; frequencies 50.001 MHz through 53.999 MHz require local coordination; and frequencies 54MHz through 72.999 MHz require local (FCC) coordination. NOTE: The reallocation of federal RF spectrum is an ongoing process. Reallocation may affect testing in some of the spectrum bands listed in Figure 18-3. The Page 246 11/17/05 Chapter 18 - continued 6050.32B MILDEP FMOs have the latest information on spectrum reallocation actions and will factor this knowledge into the national coordination process.

FIGURE 18-3a. COORDINATION LEVEL REQUIRED BY CHANNEL AND FREQUENCY Page 247 6050.32B Chapter 18 – continued 11/17/05 FIGURE 18-3b. COORDINATION LEVEL REQUIRED BY CHANNEL AND FREQUENCY Page 248 11/17/05 Chapter 18 - continued 6050.32B FIGURE 18-3c. COORDINATION LEVEL REQUIRED BY CHANNEL AND FREQUENCY Page 249 6050.32B Chapter 18 – continued 11/17/05 FIGURE 18-3d. COORDINATION LEVEL REQUIRED BY CHANNEL AND FREQUENCY Page 250 11/17/05 Chapter 18 - continued 6050.32B FIGURE 18-3e. COORDINATION LEVEL REQUIRED BY CHANNEL AND FREQUENCY Page 251 6050.32B Chapter 18 – continued 11/17/05 FIGURE 18-3f. COORDINATION LEVEL REQUIRED BY CHANNEL AND FREQUENCY Page 252 11/17/05 Chapter 18 - continued 6050.32B FIGURE 18-3g. COORDINATION LEVEL REQUIRED BY CHANNEL AND FREQUENCY Page 253 6050.32B Chapter 18 – continued 11/17/05 FIGURE 18-3h. COORDINATION LEVEL REQUIRED BY CHANNEL AND FREQUENCY Page 254 11/17/05 Chapter 18 – continued 6050.32B FIGURE 18-3i. COORDINATION LEVEL REQUIRED BY CHANNEL AND FREQUENCY 1809. thru 1899. RESERVED.

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11/17/05 6050.32B CHAPTER 19. AUTOMATED ENGINEERING 1900. PURPOSE . The purpose of this chapter is to present policy and an overview on the use of various computer system elements developed to support FAA spectrum engineering. These system elements facilitate the automation of various engineering functions used by Headquarters to evaluate and make frequency assignments.

1901. AUTOMATED FREQUENCY MANAGER (AFM) . The AFM system should be used by any FAA spectrum engineer to engineer frequencies, submit or track frequency assignment applications, investigate RFI or analyze the contents of the AFM data base, which includes data obtained from the GMF, FAA pending frequency assignments, and various international, FCC, and ARINC sources. Headquarters is responsible for engineering and recommending approval/disapproval to NTIA for all frequency assignments, both Government and non- Government, delegated to the AAG (see NTIA Manual, Chapter 1), as well as all FAA frequency assignments in all frequency bands. FAA registers all of its own frequency assignments, as well as non-Government frequency assignments in the AAG bands, with the NTIA. The frequency assignments are then incorporated into the GMF.

See paragraph 1907. The AFM is also used as a tool for frequency assignment coordination between Government entities requesting frequency assignments in the AAG bands.

1902. AFM AGENDA SYSTEM. The AFM Agenda System program is designed to allow Headquarters users to evaluate and vote on frequency assignments in a Windows environment. The program allows users to review and vote on all assignments processed by NTIA. Agenda sections are downloaded from, and voted records returned to, NTIA daily. See paragraph 1908.

1903. AIRSPACE ANALYSIS MODEL (AAM). The AAM was designed to assist the FMO in determining the effects of various radio transmitters (in particular FM stations) on aircraft navigation and communications receiver facilities. The model determines the effects of FM broadcast stations on ILS localizer and VOR signals.

It allows the selection of a proponent FM station at any location within the U.S. and provides a complete compatibility analysis between the proponent and any selected localizer within 30 nmi of the proponent. See paragraph 1909.

1904. RFI and RADHAZ DATA BASE. The Spectrum Management Data Base (SMDb) is used to record RFI events affecting the NAS, and to facilitate the calculation and reporting of radiation measurements. The SMDb significantly enhances the means to address these issues and to share information across the Technical Operations Services organizations. See paragraph 1910.

1905. EXPANDED SERVICE VOLUME (ESV) MANAGEMENT SYSTEM (ESVMS). The ESVMS is an advanced web-accessible application that provides a set of functions in an easy-to-use interface. This program was developed to improve the processing time for new ESVs and to provide an effective tool in recording and tracking all ESV requests, from origination to final approval and registration into the national ESV data base.

It provides for the generation and printing of reports for all Pending, Approved, Disapproved, Cancelled, and Restricted ESVs. See paragraph 1911.

1906. RADIO COVERAGE ANALYSIS SYSTEM (RCAS). RCAS is a web-accessible modeling and analysis tool used to perform radio coverage and analysis studies. RCAS allows a visualization of the predicted radio coverage patterns, taking into account terrain data. This tool also facilitates the siting of communications, navigation, and radar equipment. This can be done by overlaying the analysis with state boundaries, sector boundaries, ground features, etc.

Page 261 6050.32B Chapter 19 - continued 11/17/05 1907. OVERVIEW OF THE AFM a. The AFM. The AFM software application is an Internet based application consisting of primarily Client, Business/Application, and Data base service/server tiers. Service area users can access the AFM Internet based application via the FAA Network, the Internet via a Secure Socket Layer (SSL) or a secure Virtual Private Network (VPN) connection, as well as a Dial-up Remote Access Server (RAS) connection. Service area users can also run and access program files and the data base locally if necessary.

b. Uses.

(1) Create and modify FAA and NG applications , edit them to ensure they conform to FAA and NTIA standards and send them to NTIA for incorporation into the GMF.

(2) Track the progress of applications through the approval process.

(3) Produce management reports on the status of the assignment process.

(4) Produce new FTA forms as applications are approved.

(5) Register frequencies internationally (planned future application).

(6) Review assignments regularly (at least every 5 years) to ensure that the frequencies are still in use and the assignments correctly reflect the usage.

(7) Create and modify DOD and other Government applications in the AAG bands to test for frequency suitability, i.e., to provide coordination with other agencies.

c. Frequency engineering . Each proposed frequency shall be tested to ensure that it meets FAA standards for sufficient signal strength within its FPSV and receives the required protection from interference. The AFM system provides several models for engineering interference-free frequencies. These models protect both the proposed target and all existing sites, i.e., testing is done on the target as both desired and undesired. These models assist the user in engineering and selecting the best frequency to assign for the most efficient use of the spectrum. The model's results detail reasons for failure/interference, thus assisting the user in exploring ways to engineer a successful frequency, e.g., by using filters, changing the power, etc.

(1) The Air/Ground model is a tool for engineering frequencies in the 118-137 MHz and 225-400 MHz bands. This model performs the following tests, which are further described in Chapter 9 and Appendix 2.

(a) A cochannel test protects against using the same frequency in two coverage areas within interference range of each other.

(b) An adjacent channel test protects against using frequencies separated by ± 25 kHz or ± 50 kHz from being used in nearby service areas, which otherwise could result in interference.

(c) A cosite test protects against the potential for interference from nearby transmitters, which otherwise would be allowed to operate at a frequency separation less than an established minimum, usually ± 500 kHz for VHF or ± 1 MHz for UHF.

(2) The NAVAIDS Model perform s intersite analysis tests in the bands 108.20-117.95 MHz (LOC, VOR/VOT), 328.6-335.4 MHz (GS), 960-1215 MHz (DME/TACAN), and 5031-5091 MHz (MLS). For GS and MLS testing, cochannel and adjacent channel testing involves identifying those sites having interferers within Page 262 11/17/05 Chapter 19 - continued 6050.32B designated distances. For DME/TACAN, VOR/VOT, and LOC testing, an Equivalent Signal Ratio (ESR) is calculated and the interpolation of appropriate curves is carried out to determine the required separation distance, as described in Chapter 10 and Appendix 3 of this manual. If ESVs are associated with the target or potential interferer, they are also tested. The target's ESV signal strength is also tested. In order to protect paired NAVAID frequencies, dummy assignments have been created for unassigned associated frequencies.

(3) The NDB model tests nondirectional beacons in the frequency band 190-535 kHz. All potential interferers within a frequency ± 6 kHz from the proposed target are tested. The required separation distance is calculated, based upon the prediction curves and calculation methods described in Chapter 11 of this manual.

(4) Frequency assignments for fixed, mobile communications, HF communications, radio communications links, and radar are tested by using a generic model, which produces a circle report of potential interferers.

d. OTHER AFM ENGINEERING FEATURES . Additional features of the AFM assist spectrum engineers in performing engineering analyses. FCC, ARINC, and international data bases are maintained and are used by the models and browse/query routines.

(1) Browse and query routines are provided to assist engineers in analyzing the distribution of frequencies throughout the spectrum.

(2) A graphics routine lets users display model and browse/query results on appropriate maps. Users can also choose to map ILS keyholes, glide slope and ESV wedges, DME/VOR circles, and TSV ATC sectors.

(3) An intermod program helps engineers investigate possible sources of RFI. The frequencies tested as well as the potential interferer frequencies can be user-entered, selected from a browsed list, and/or selected from a circle report.

(4) A TSV data base is periodically updated. The Centrad model lets users modify a pending TSV data base. The A/G model as well as the graphics routines uses these data bases.

(5) ESV data can be added to NAVAIDS assignments. The NAVAIDS model is used to test ESVs for signal strength and interference.

(6) Engineering tools are also provided. These include bearing/distance calculations and power/density calculations.

(7) The system documentation includes formulas used in creating the models and tools. This documentation is included in the on-line help.

1908. AFM AGENDA SYSTEM. This system allows FAA Technical Operations ATC Spectrum Engineering Services users to vote on "frequency applications" submitted by other government agencies via records received from the NTIA.

a. The system is comprised of three programs: Import, Export, and Vote Agenda.

(1) Import is run daily to import all new "sections" of data from NTIA.

(2) Export is run daily to export all "voted" applications to NTIA.

Page 263 6050.32B Chapter 19 - continued 11/17/05 (3) Technical Operations ATC Spectrum Engineering Services users can run the Vote Agenda program, throughout the day, to review and vote "applications."

b. Vote Agenda. Users log into the system using a User ID that identifies which AFM frequency "bands" the user can access and review. A band access table identifies the frequency bands each user can access and it is user modifiable.

1909. AIRSPACE ANALYSIS MODEL (AAM) a. Overview of the AAM (1) The primary purpose of the AAM is to serve as a tool to help evaluate the effects of FM broadcast signals on ILS localizer, VOR and COMM signals received by airborne receivers, as well as by ground receivers in the case of COMM. This includes intermodulation, receiver front-end overload and adjacent channel interference.

(2) This model differs significantly from earlier methods of analyzing compatibility in that a complete three dimensional analysis is performed. This analysis takes into consideration the vertical radiation patterns of the FM broadcast antennas as well as the vertical structure of the Navaid service volume. The output of this model consists of computer-generated plots, which indicate regions within the Navaid service volume where interference is predicted.

(3) The AAM consists of standard RF propagation equations and a quantity of empirical data acquired from various sources involved in the investigation of the compatibility between FM broadcast and aeronautical radio services. The data were obtained from measurements performed on a range of equipment under a variety of conditions. A mathematical representation of the data is used to categorize the immunity performance of a representative receiver under a wide range of signal conditions.

(4) The potential for RFI is determined by calculating the signal conditions present at a specific site by identifying the relevant RF emitters in the area, applying standard propagation equations and adjusting for system losses to find the signal levels at the receiver input, and then examining the empirical data to see if the representative receiver would experience interference under those conditions.

b. Signal Level Prediction (1) The AAM calculates the signal-in-space conditions by starting with the parameters of the transmitting system and accounting for propagation loss. Transmitting parameters for an FM broadcast station include the transmitter power as well as the vertical and horizontal gain patterns of the transmitting antenna. For aeronautical facilities, the AAM accesses a subset of the GMF to determine the array type of the facility being analyzed and then performs the needed calculations to determine the signal-in-space conditions. For example, signal levels for the localizer are calculated by modeling the free-space, vertical pattern of the localizer as a Sin θ pattern. Ground reflections are modeled by assuming the ground to be an infinite, flat plane with a dielectric constant of 12 and a conductivity of .003 Mhos per meter.

(2) The signal-in-space value is then corrected by the losses in the receiving system (including losses due to the frequency-gain response of the receiving antenna) to determine the levels of the signals (both desired and undesired) present at the input to the receiver.

Page 264 11/17/05 Chapter 19 - continued 6050.32B c. Interference Calculations (1) Several receiver models have been examined through a series of bench measurements taken by the FAA and the FCC. The receivers were chosen to represent a broad cross-section of the existing population.

Statistics on the population of receivers and aircraft were obtained from the FAA, the NTSB, the General Aviation Manufacturers Association (GAMA), and the AOPA. The receiver models included in the measurements constitute combined sales of more than 200,000 units spread among the 215,000 active civil aircraft in United States (including air carrier, commuter, and general aviation categories).

(2) Various combinations of these receivers were tested for sensitivity to interference by overload/desensitization (type B2), adjacent channel (type A2), and two-signal/three-signal third-order intermodulation (type B1). The results were tabulated and used to develop empirical interference threshold criteria. A step-by-step description of the AAM calculations in shown below.

(a) The AAM identifies the boundaries of the FPSV for the aeronautical facility of interest and generates a grid of test locations throughout the area of interest within the FPSV. This grid is on a maximum spacing of 1000' x 1000' centers for the ILS localizer, a maximum spacing of 6076' x 6076' centers for the VOR, and a maximum spacing of 2 percent of the service-volume radius or 9999', whichever is less, for VHF communications facilities (except for ground-based VHF communications facilities which are only examined at the location of the facility).

(b) The AAM identifies the undesired RF emitter sources and calculates the field-in-space for every emitter, at every grid location, based on the transmitted power, the radiation patterns of the transmitting antennas, and the propagation losses.

( c) The AAM adjusts the field-in-space values for receiving system losses (including the frequency vs. gain response of the receiving antenna and polarization loss) to determine the signal levels at the receiver input for both the undesired signals and the aeronautical signal.

(d) The AM applies the A2 (adjacent-channel) and B2 (overload/desensitization) interference criteria at every grid location for every undesired emitter to determine if the representative receiver will experience A2/B2 interference based on the signal levels at that grid location.

(e) The AAM identifies every relevant RF emitter (including broadcast and aeronautical facilities) located within 30 nmi of the FPSV boundaries and computes every potential two-signal and three-signal, third- order intermodulation (IM) product. It then identifies every IM product falling within 200 KHz of the aeronautical facility being studied.

(f) The AAM calculates the signal levels [using the parameters discussed in step (a) and step (b) above] of every component of every IM product identified in step (e), and applies the B1 (IM) interference criteria to determine if the representative receiver will experience B1 interference based on the signal levels at that grid location.

(g) A map of the FPSV is generated containing a plot of every grid location at which interference is predicted to occur.

1910. RFI AND RADHAZ SUPPORT a. The SMDb provides automated tools to help satisfy analysis and reporting functions for both RFI and RADHAZ cases, as highlighted in paragraph 1904. The capabilities and operational environment of the SMDb are briefly highlighted below.

Page 265 6050.32B Chapter 19 - continued 11/17/05 b. The RFI portion of the SMDb application enables users to record RFI events affecting the airspace for which they manage the radio spectrum. Recording these events is accomplished through an easily accessible application with improved navigation and functionality. This application also allows for the sharing of resolution information across the Technical Operations Services organizations. The RFI portion of the SMDb supports the following: (1) Provides a library of audio files capturing the sound of recorded interferences to be accessed through the FAA intranet 24 hours a day, seven days a week.

(2) Serves as a reporting system. Many ad hoc queries can be performed on the data collected in this system.

(4) RFI reports are entered and viewed through a number of means. The SMDb is envisioned to be the one place to report, record RFI and collect information concerning ongoing investigations, as well as view historical data on events from previous years. Service areas, as well as Headquarters, can use this repository to view all interference problems and their resolution.

(5) Uploading any type of file to be linked with the Interference Record.

(6) Records the funds expended to investigate the RFI.

(7) Add utility screens for choices which did not previously exist to drop-down boxes in a simple manner, without the use of a programmer. These screens can be accessed from the menu panel.

(8) Maintain data integrity through many validations. For example, if the frequency, facility type, and facility identifier do not match the frequency assignment listed in the AFM, the system will not allow an RFI event to be recorded against that facility.

c. The RADHAZ portion of the SMDb facilitates the calculation and reporting of Radiation Measurements, from the time of a RADHAZ request through the reporting and approval of the measurements. It is also acts as a repository of all FAA RADHAZ survey reports. The RADHAZ portion of the SMDb supports the following: (1) Upload an electronic version of a RADHAZ report document (scanned or original) to be linked to a facility record and include it in a RADHAZ online repository.

(2) Download available RADHAZ reports in online repository for viewing purposes.

(3) Write and print RADHAZ reports using a predetermined format, including writing and submitting special request or baseline RADHAZ survey reports.

(4) Approve and publish reports by an approving authority, from reports submitted by a user.

(5) Search and view RADHAZ survey reports related to a specified facility.

d. SMDb Operating Environment. The SMDb resides as a web-based application on the FAA’s Intranet.

Users access the system using Microsoft Internet Explorer web browser. The SMDb does not have a "client" software application. Most application functions will occur centrally on the server either using the web application server or the data base server. FAA personnel will have access to data in a "real-time" environment.

Updates to data made by a user will be instantaneously available to all other users having access to the application.

Page 266 11/17/05 Chapter 19 - continued 6050.32B 1911. ESV a. Background. ESVs are not registered in the NTIA or GMF. Thus, Technical Operations ATC Spectrum Engineering Services maintains a separate data base within the AFM system for all ESVs used in the NAS. The ESV process previously required the procedures specialist to apply for an ESV by FAA Form 6050-4 that requires FMO and FIFO approval. The development of the ESVMS provides an automated and much more flexible means of processing ESVs.

b. Capabilities. The ESVMS enables users to process ESV requests to establish, revise or cancel ESVs. It provides an enhanced workflow with on-line tracking of ESV requests 24 hours a day, seven days a week. During the process, users have the ability to view the status of all ongoing ESV requests through an easily accessible system using intuitive format and navigation. ESVMS gives the user the option of saving an application while it is being worked on and selecting it again, at another time, to complete and send forward in the process. The system offers administrative users the functionality to manage and update user information and privileges. The ESVMS also presents the capability of reporting detailed and summary data.

c. Operating Environment . The ESVMS resides on a web application server and operates on the FAA's Intranet. Users may access the system using Microsoft Internet Explorer web browser. The ESV application does not have a "client" software application. Most application functions will occur centrally on the server either using the web application server or the data base server. All concerned FAA entities will have access to data in a "real- time" environment. Updates to data made by any user will be instantaneously available to all other users having access to the ESVMS.

1912. – 1999. RESERVED Page 267 (and 268)

11/17/05 6050.32B APPENDIX 1. AIRSPACE EVALUATION SECTION 1. BACKGROUND AND PROCEDURES 1. INTRODUCTION . The authority, regulations, and basic procedure for handling airspace evaluations are discussed in chapter 5. This appendix will establish detailed methods for such evaluations.

2. BACKGROUND . Due to the rapid growth of both aeronautical and commercial broadcast services, the number of interference cases involving aircraft and commercial broadcast emissions has increased dramatically.

Interference is usually most severe at airports with high power FM and TV broadcast facilities nearby.

a. COMM receivers experience interference in the form of nuisance background noise, actual broadcast audio, and distorted or garbled reception of desired ground transmissions. NAVAID receivers (VOR and LOC) experience nuisance audio, actual errors in course deviation indicators, and erroneous flag indications. This interference to NAVAID receivers is the most serious. Course deviation errors during an approach and landing, the most critical phase of flight operation, are usually not as evident to the pilot as disrupted communications.

b. There are many factors that contribute to this problem. One is the broad power differential between commercial broadcast and aeronautical service transmitters. FM stations may operate at as much as 100 kW and many TV stations operate above the 100 kW level. In contrast, a LOC transmitter is typically operated at only 20 W, plus 12 to 20 dB gain “on course.” Outside the LOC antenna's main beam, the EIRP is considerably reduced.

c. There is no guard band between the high end of the FM broadcast band (107.9 MHz) and the low end of the aeronautical NAVAID band (108.0 MHz). Spurious emission levels from commercial transmitters are significant as far as 600 kHz off channel. Also, due to operating necessity, the minimum performance standards for aircraft receivers require them to be a broadband device.

3. FM BROADCAST TOLERANCES . FCC Rules and Regulations Part 73 authorize the operation of FM broadcast transmitters within certain standards and tolerances.

a. FMOs should review Part 73 which establishes policy that proponents who either (1) commence program tests, or (2) replace their antennas, or (3) request facility modifications and are issued a new construction permit, must satisfy all complaints of interference to aeronautical facilities during a one year period. Resolution of complaints will be at no cost to the FAA.

b. FM broadcast stations operate on 100 channels in the 88-108 MHz band (see figure 1). Channel carriers are 200 kHz apart on odd decimal frequencies. The first assignable channel is 88.1 MHz (Ch 201) and the last is 107.9 MHz (Ch 300). The FCC allocates FM channels to towns and cities across the nation according to a coordinated geographic assignment plan.

Page 1 6050.32B Appendix 1, Section 1 – continued 11/17/05 FIGURE 1. FM CHANNELS AND CENTER FREQUENCIES CHNL FREQ CHNL FREQ NO. MHZ NO. MHZ 201 88.1 251 98.1 202 88.3 252 98.3 203 88.5 253 98.5 204 88.7 254 98.7 205 88.9 255 98.9 206 89.1 256 99.1 207 89.3 257 99.3 208 89.5 258 99.5 209 89.7 259 99.7 210 89.9 260 99.9 211 90.1 261 100.1 212 90.3 262 100.3 213 90.5 263 100.5 214 90.7 264 100.7 215 90.9 265 100.9 216 91.1 266 101.1 217 91.3 267 101.3 218 91.5 268 101.5 219 91.7 269 101.7 220 91.9 270 101.9 221 92.1 271 102.1 222 92.3 272 102.3 223 92.5 273 102.5 224 92.7 274 102.7 225 92.9 275 102.9 226 93.1 276 103.1 227 93.3 277 103.3 228 93.5 278 103.5 229 93.7 279 103.7 230 93.9 280 103.9 231 94.1 281 104.1 232 94.3 282 104.3 233 94.5 283 104.5 234 94.7 284 104.7 235 94.9 285 104.9 236 95.1 286 105.1 237 95.3 287 105.3 238 95.5 288 105.5 239 95.7 289 105.7 240 95.9 290 105.9 241 96.1 291 106.1 242 96.3 292 106.3 243 96.5 293 106.5 244 96.7 294 106.7 245 96.9 295 106.9 246 97.1 296 107.1 247 97.3 297 107.3 248 97.5 298 107.5 249 97.7 299 107.7 250 97.9 300 107.9 Page 2 11/17/05 Appendix 1, Section 1 - continued 6050.32B c. Maximum spurious emission levels for FM broadcast stations are: Any spurious emission Must be attenuated removed from the main below the unmodulated carrier frequency by : carrier by at least: 120-240 kHz 25 dB 240-600 kHz 35 dB Beyond 600 kHz 43 dB + 10 Log P or 80 dB, whichever is the lesser (P = power output in watts) d. An FM transmitter operates with a maximum allowable deviation of ±75 kHz around the carrier. Actual deviation is governed by the amplitude of the modulating signal and the rate of deviation is determined by the modulating frequency. An infinite number of sidebands theoretically results. Only sidebands down to 1 percent of the carrier amplitude are considered significant. Therefore, the total occupied bandwidth of an FM broadcast emission extends beyond ±75 kHz, but is subject to the spurious emission standards stated in subparagraph b. and shown in figure 2.

Page 3 6050.32B Appendix 1, Section 1 – continued 11/17/05 FIGURE 2. SPURIOUS EMISSION LEVEL OF AN FM BROADCAST TRANSMITTER ON 107.9 MHZ e. The radiated power of an FM station is set by FCC standards, according to the class of station and the transmitter antenna height. Power can be up to 600 kW in some cases.

f. The horizontal radiation pattern of a typical FM broadcast antenna is considered omnidirectional. The vertical pattern is a function of the gain and number of elements (bays) used by the antenna. Antenna radiation polarization may be horizontal, vertical or both.

4. TV BROADCAST TOLERANCES . FCC Rules and Regulations Part 73 authorizes the operation of TV broadcast transmitters within certain standards and tolerances.

a. TV broadcast stations operate on 12 VHF channels between 54-216 MHz and 56 UHF channels between 470-806 MHz (see figure 3). Channel carriers are 6 MHz apart. FCC allocates TV channels to towns and cities across the nation according to a coordinated geographic assignment plan.

b. The visual carrier is 1.25 MHz (±1 kHz) above the channel lower limit and may be offset by ±10 kHz.

The aural carrier is 0.25 MHz (±1 kHz) below the upper channel limit (see figure 4).

c. The minimum radiated power for all classes of TV stations is 100 W.

Page 4 11/17/05 Appendix 1, Section 1 - continued 6050.32B d. Maximum power for TV stations is set by FCC standards according to the operating frequency (channel), geographical location and transmitter antenna height. Radiated power can reach as high as 5 MW for UHF channels under some conditions.

e. The TV broadcast transmission consists of the amplitude modulated visual carrier with a composite picture and synchronizing signals, together with the aural carrier frequency modulated by the audio signal. A vestigial sideband filter reduces the lower sideband width.

f. Spurious emissions , including RF harmonics, are required to be maintained at as low a level as the state of the art permits. All emissions removed in frequency in excess of ±3 MHz of the respective channel edge shall be attenuated no less than 60 dB below the visual transmitted power. These levels are measured at the output terminals of the transmitter.

g. Directional antennas may be employed to improve coverage. Polarization may be horizontal or circular.

The maximum to minimum ratio of radiation in the horizontal plane shall not exceed 10 dB for channels 2-13 and 15 dB for channels 14-69.

5. AM AND OTHER NONBROADCAST STATION STANDARDS . Other stations such as AM, cellular, microwave, etc. have different standards. For these facilities, the airspace evaluation is handled differently. Refer to Chapter 8 of this Order, paragraph 808.

6. STANDARD FPSVS FOR FAA FACILITIES . The FPSVs for various facilities are discussed in detail in the portions of this order pertaining to specific types of equipment. Of concern in this appendix are the ILS LOC and VOR FPSVs. The standard and optional service volume dimensions for ILSs and VORs are shown in Appendix 3.

Page 5 6050.32B Appendix 1, Section 1 – continued 11/17/05 FIGURE 3. TV CHANNELS AND ASSOCIATED FREQUENCIES CHNL FREQ CHNL FREQ NO. MHZ NO. MHZ 2 54-60 36 602-608 3 60-66 37 608-614 4 66-72 38 614-620 5 76-82 39 620-626 6 82-88 40 626-632 7 174-180 41 632-638 8 180-186 42 638-644 9 186-192 43 644-650 10 192-198 44 650-656 11 198-204 45 656-662 12 204-210 46 662-668 13 210-216 47 668-674 14 470-476 48 674-680 15 476-482 49 680-686 16 482-488 50 686-692 17 488-494 51 692-698 18 494-500 52 698-704 19 500-506 53 704-710 20 506-512 54 710-716 21 512-518 55 716-722 22 518-524 56 722-728 23 524-530 57 728-734 24 530-536 58 734-740 25 536-542 59 740-746 26 542-548 60 746-752 27 548-554 61 752-758 28 554-560 62 758-764 29 560-566 63 764-770 30 566-572 64 770-776 31 572-578 65 776-782 32 578-584 66 782-788 33 584-590 67 788-794 34 590-596 68 794-800 35 596-602 69 800-806 Page 6 11/17/05 Appendix 1, Section 1 - continued 6050.32B FIGURE 4. IDEALIZED STANDARD TV CHANNEL SPECTRUM 7. EVALUATION PROCEDURE OUTLINE . It is essential that airspace case study methods be thorough and consistent from service area to service area. An improper evaluation may cause difficult and lengthy legal proceedings for the agency. The outline presented in figure 5 is a guide for each evaluation.

8. DATA ASSEMBLY .

a. It is difficult to establish specific sources for retrieving the data necessary for an evaluation. Commercial broadcast data exist as hard copy listings and additional information can be obtained through FCC or from the broadcasters themselves. The AM, FM and TV data bases are available through the automated frequency management system (AFM).

b. When identifying commercial broadcast stations for an aeronautical study, specific radii have been established for each of the broadcast services based on probability and empirical tests. The greatest potential for interference comes from high power FM, particularly those stations operating at the high end of the FM band.

c. FAA and non-Fed facilities may be identified using the CIRCLE program or other search programs available through the AFM. If the proposed construction is an FM transmitter, the search should be for a 30 nmi radius around the new coordinates; if for a TV transmitter, 10 nmi; if for AM, 3 nmi.

Page 7 6050.32B Appendix 1, Section 1 – continued 11/17/05 FIGURE 5. EVALUATION PROCEDURE OUTLINE CHART A. ASSEMBLE DATA 1) Commercial stations a. Frequency b. Coordinates c. Power (EIRP) d. Site elevations e. Antenna height (AGL, AMSL, RCAMSL) f. Antenna types and radiation patterns 2) FAA facilities a. Frequency b. Coordinates c. FPSVs d. Site elevations e. Antenna height (AMSL) f. Associated facilities 3) Charts a. Low Altitude Sectional Charts b. VFR Terminal Area Chart c. Instrument Approach Plates d. Topographical Maps (if necessary) B. INTERMOD STUDY 1) Obtain third order intermod products 2) Use bandwidth of FAA facilities (usually ±100 kHz NAV and ±50 kHz COMM) 3) Include facilities within appropriate radii C. GROUND FACILITIES 1) Calculate out-of-band signal level 2) Calculate in-band signal level 3) Include vertical patterns if necessary D. AIRBORNE RECEIVERS 1) NAV interference — Use the Airspace Analysis Model to determine interference from FM broadcast stations to ILS localizer signals and VOR.

2) COMM interference (include vertical patterns if necessary) a. Calculate brute force radius b. Plot Venn diagrams along with FPSVs c. Calculate intermod radii Page 8 11/17/05 Appendix 1, Section 1 - continued 6050.32B d. Once these transmitters have been identified, specific data should be compiled for each. These shall include the station frequency, geographic coordinates, power (EIRP), terrain elevation, antenna elevation above mean sea level (AMSL) or above ground level (AGL), radiation center above mean sea level (RCAMSL), radiated power and possibly the radiation pattern of the antenna. When dealing with a TV transmitter, use the visual carrier frequency for all calculations, 1.25 MHz above the bottom frequency of the channel assignment; e.g., CH2 video carrier is 55.25 MHz within channel limits of 54-60 MHz.

e. The search should provide frequency, geographic coordinates, power (EIRP), terrain elevations, antenna elevations AGL and AMSL, FPSVs and associated facilities. The CIRCLE program automatically provides all these, plus the distance of each facility from the search coordinates.

f. NAVAID frequencies between 108.1-108.9 MHz and FM frequencies between 107.1-107.9 MHz particularly should be scrutinized. If a high power high band FM and a low band NAVAID are located within 30 nmi of each other, the likelihood of interference is high and requires very careful analysis. VHF TV channels 4 and 5 bracket the frequency used for ILS marker transmitters, 75 MHz, so careful analysis is required when these channels are proposed near ILS marker facilities.

g. AM, TV and non-broadcast sources should be plotted and studied in accordance with procedures outlined in sections 2 and 3 of this appendix.

h. FM sources are covered under the Airspace Analysis Model (AAM) program described in section 2 of this appendix.

9. INTERMOD STUDY .

a. A receiver will experience intermod interference whenever two or more signals or their integer multiples combine in such a manner that the product is the frequency to which the receiver is tuned ( f ). These signals O combine in the nonlinear receiver input and other nonlinear external devices to produce sum and difference frequencies through heterodyne action. If a strong signal causes the receiver input to be overdriven, the effect is more pronounced.

b. These intermod products are of the following form: Af ± Bf = f Af + Bf – Cf = f 2Af ± Bf = f 1 2 0 1 2 3 0 1 2 0 c. The order of the intermod product is the sum of the coefficients in the formulas (A, B, and C). Products through the third order are of primary concern to airspace studies. Intermod calculations are very tedious. There are several desk calculator and computer programs available that will run all desired orders of intermod by just entering the subject frequencies. Consideration also must be given to the bandwidth of the victim receiver which is f ± bandwidth.

O 10. GROUND FACILITIES.

a. Both VHF and UHF ground receivers require protection from nearby commercial FM and TV broadcast stations. They may be affected by spurious (in-band) emissions and single frequency overload (out-of-band) interference. The latter is often referred to as "brute force" interference.

Page 9 6050.32B Appendix 1, Section 1 – continued 11/17/05 b. The major factors involved in calculating interference from spurious emissions (in-band) are the receiver sensitivity, the FCC-specified spurious emission limits, and the offending EIRP. Antenna, filter and receiver selectivity have no effect, since the spurious signal is an on-frequency interference. Spurious interference will result if the signal level from the broadcast station at the on-frequency input to the victim receiver exceeds -104 db above one milliwatt (dBm). This is calculated as: LEVEL = EIRP - L - L - L - L - S v d p r r IN-BAND level at victim frequency cannot exceed –104 dBm Where: EIRP = Power of the potential interfering station in dBm.

[ EIRP (in dBm) = 10 log (power in kW) + 62.2] L = Free space transmission loss in dB at the victim receiver frequency.

v L = Antenna vertical directivity loss in dB. This term requires antenna pattern data from the d proponent. If the value is unknown, use 0 dB.

L = Polarization loss between the victim and broadcast antennas in dB. If the broadcast antenna p is horizontally polarized, L = 16 dB; if circularly polarized, p use 0 dB.

L = Receiver system on-frequency losses in dB. If value is unknown, use 3 dB.

r S = FCC spurious emission tolerance in dB. Use 80 dB for FM transmitters and r 60 dB for TV transmitters, except where the calculated value is less.

Example of S calculation: r The FCC spurious emission limit for FM is: 43 + 10 log ERP or 80 dB, whichever is lesser (Watts) For an FM station with an ERP of 10 kW = 10,000 W: 10 log 10,000 = 10 x 4 = 40 Spurious limit = 43 + 40 = 83 (Note that any power >5,000 W would be limited to -80 dB suppression.)

For an FM station with an ERP of 1,000 W: 10 log 1,000 = 10 x 3 = 30 Spurious limit = 43 + 30 = 73 Since 73 < 80, the spurious limit for this station is -73 dB from the main carrier.

For a TV station, the formula is: 43 + 10 log ERP or 60 dB, whichever is lesser.

(Watts) Page 10 11/17/05 Appendix 1, Section 1 - continued 6050.32B c. Ground RCF antenna gains vary considerably over the VHF and UHF range of possible interference.

Plots of those gains through 800 MHz are shown in figure 6.

FIGURE 6. TYPICAL FAA VHF AND UHF RCF GROUND ANTENNA GAIN VS. FREQUENCY PLOTS Page 11 6050.32B Appendix 1, Section 1 – continued 11/17/05 d. The Intermediate Frequency (IF) selectivity of a ground receiver will not provide any protection from single frequency front end overload because this effect occurs in the receiver RF section which will respond to most frequencies within the commercial broadcasting bands. Tests have shown that a high power signal at the input to the victim receiver will overload the RF section when it exceeds -4 dBm . This level is calculated from the following relationship: LEVEL = EIRP – L - L – L – L - L i d p r a OUT-OF-BAND level cannot exceed -4 dBm where: EIRP = Power of the potential interfering station in dBm.

[ EIRP (in dBm) = 10 log (power in kW) + 62.2] L = Free space transmission loss in dB at the frequency of i the potential interfering station.

L = 20 log (freq in MHz x D in ft) - 37.9] i a L = Antenna vertical directivity loss in dB. This term requires antenna pattern d data from the proponent. If the value is unknown, use 0 dB.

L = Polarization loss between the victim and broadcast antennas in dB. If the p broadcast antenna is horizontally polarized, L = 16 dB; if circularly p polarized, use 0 dB.

L = Receiver system on-frequency losses in dB. If value is unknown, use 3 dB.

r L = Typical A/G antenna loss in dB. If unknown, use 3 dB.

a e. The slant range distance D in feet between antennas is calculated using the Pythagorean theorem. One a side of the right triangle is the difference in the antenna heights (AMSL) X in feet and the other side d is the distance in feet between the antenna coordinates. The slant distance (D ) will then be the hypotenuse of the a triangle. See figure 7. The GROUND.WK1 computer program works this out automatically, or to calculate the distance (in feet) between the antenna coordinates, use the following method: 2 2 D d X = +

( )

a Distances in feet between two locations expressed in coordinates can be determined by any of the great circle distance computer programs readily available, or if close, can be measured by tape.

Page 12 11/17/05 Appendix 1, Section 1 - continued 6050.32B FIGURE 7. EXAMPLE OF A PLOT FOR CALCULATING SLANT RANGE 11. AIRBORNE RECEIVERS . Data obtained through a series of bench and flight tests conducted by the FAA at the FAA William J. Hughes Technical Center has established the signal strength levels required for intermod and brute force interference to occur. These data have been incorporated into the AAM which is used for all evaluations of the effects of FM broadcast station on ILS localizers and VORs. Testing to add COMM receivers and other FAA facilities as well as other potential interferers is currently underway. Until that testing is finished, the Venn diagram method described below will be used for all situations not covered by the AAM.

a. For brute force predictions , signal levels of -10 dBm or greater are necessary. To produce intermod interference, at least one of the combining frequencies must be at a prime level, while the others are at a secondary level. The prime level will overdrive the receiver causing the nonlinearity required for heterodyning.

For COMM receivers the prime level is -10 dBm and for NAV receivers, -20 dBm . In both receivers the secondary level is -30 dBm .

b. Since most commercial stations radiate omnidirectionally , these power contours can be constructed in the form of Venn diagrams. Wherever the Venn diagrams of prime and secondary signal levels overlap, intermod interference can be expected. Whenever the -10 dBm contour intersects a NAV or COMM FPSV, receiver overload will occur, regardless of the receiver frequency. If the station uses a directional antenna, the Venn diagram would have to be modified to match the contour level of radiation of the particular antenna.

Page 13 6050.32B Appendix 1, Section 1 – continued 11/17/05 c. These contour distances can be calculated using a form of the space loss formula: anti EIRP P L − − − log ( . ) / 37 8 20

[ ] r r

d = f Where: EIRP = Power of the station in dBm (ERP + 2.2) P = Value of the desired signal strength (-10, -20, -30 dBm) r L = Antenna loss of aircraft [See data in subparagraphs (1) and (2)] r 37.8 = Free space loss conversion for distance in nmi d = distance of Venn radius in nmi f = station frequency in MHz (1) L for COMM antennas : r Above 175 MHz 15 dB 100-108 10 dB 88-108 10 dB + 2 dB/MHz below 100 MHz Below 88 34 dB + 0.5 dB/MHz below 88 MHz (2) L for NAV antennas : r Above 175 MHz 15 dB 88-108 03 dB + 1 dB/MHz below 108 MHz Below 88 23 dB + 0.5 dB/MHz below 88 MHz d. A plot of these functions is shown in figure 8.

e. Except for ILS localizer and VOR frequencies , if IM products exist at any FAA frequency, the Venn diagram procedure must be applied. Plot the locations of the offending stations on a chart along with the location of the FAA facility and/or its FPSV. Calculate the Venn diagram contour distances for prime and secondary levels according to the type of receiver effected. Plot these contours on the chart and note the intersecting areas.

If the intersecting areas fall within the FPSV of the victim COMM facility, interference is probable.

f. The same procedure is followed for brute force interference. Plot the location of the offending station and construct only the -10 dBm contour. If this contour intersects the FPSV of any COMM or NAV facility, interference is probable while the aircraft is flying through the area. The frequency to which the aircraft receiver is tuned is irrelevant for brute force interference.

g. The AAM is to be used for all evaluation of the effects of FM broadcast proponents to ILS localizers and VORs. Detailed instructions on using the AAM as well as technical background on the AAM is contained in the User's Manual and Technical Reference for the Airspace Analysis Model . This document is available from Technical Operations ATC Spectrum Engineering Services.

12. SAMPLES . Samples of obstruction evaluation (OE) case studies will be found in the following sections 2 and 3 of this appendix. Figure 9 is the form filed by the proponent with typical data inserted.

Page 14 11/17/05 Appendix 1, Section 1 - continued 6050.32B FIGURE 8. RELATIVE GAIN OF AIRBORNE COMM AND NAV ANTENNAS Page 15 6050.32B Appendix 1, Section 1 – continued 11/17/05 FIGURE 9a. FAA FORM 7460-1, NOTICE OF PROPOSED CONSTRUCTION OR ALTERATION Page 16 11/17/05 Appendix 1, Section 1 - continued 6050.32B FIGURE 9b. ADDENDA TO FAA FORM 7460-1, NOTICE OF PROPOSED CONSTRUCTION OR ALTERATION Addenda to FAA Form 7460-1 Re: WASR-FM 8-14-95 MARKEY BROADCAST ENGINEERING CONSULTANTS 1060 Coronado St.

Marlboro, MD 20772 Re: WASR-FM application for new FM station Antenna Tower.

The proposed antenna is a guyed 335' tower, with 5-bay loop and 5-bay vertical dipole array, side- mounted antennas, with antenna array tops not exceeding the supporting tower height. The p roposed Frequency is 103.7 MHz, @ 43 kW ERP.

It is proposed that painting and lighting not be required, as there is a 550' tower 123' due North o f the proposed tower, which is painted and lighted per FAA/FCC requirements.

FIGURES 10. thru 14. RESERVED.

13. thru 16. RESERVED .

Page 17 (thru 22)

11/17/05 Appendix 1 - continued 6050.32B SECTION 2. ENGINEERING PROCEDURES FOR OE CASES FOR FM BROADCAST AND ILS/VOR 17. PURPOSE. The purpose of these procedures is to determine whether a new FM broadcast station (88-108 MHz) can be safely operated without causing destructive RFI to an in-place or proposed FAA ILS or VOR. (See appendix 3 for using the AAM to check ILS frequency proposals.)

a. Both airborne receivers aboard aircraft and FAA ground receivers are to be considered. The FMO conducts a study, then makes a recommendation to the appropriate service area air traffic organization as to whether to concur or non-concur. Simultaneously, while the FMO is studying the RFI potential, other services in the service area office are studying whether the new tower or structure would have an adverse effect on the safe and efficient use of airspace. A non-concur recommendation can stop the proponent (PROP) from getting FCC approval for the station. The engineering study that results in the decision must be carefully and thoroughly done, since there are considerable political and financial pressures involved.

b. Referring to the PROP's location , a check is made to find the nearest FAA or military A/G VHF or UHF communications facility within RLOS. Once located, the FM station's anticipated signal level at that site is determined. The frequencies involved are 118-137 MHz and 225-400 MHz. If the PROP's out-of-band signal level is calculated to exceed -4 dBm, the decision is non-concur , because at that level ground receivers will overload and function improperly. If the in-band spurious emission level would exceed -104 dBm, then a concur with comment determination is made. This states that the frequency management office will concur provided sufficient additional attenuation is provided by the PROP for the above bands to assure that the -104 dBm or better level is met within those bands. See paragraphs 10 and 11, Section 1 of this appendix.

c. These same levels are used for other sources of potential RFI, such as Police and Fire transmitters, Radio Paging transmitters and any of the many sources in the FCC's Radio Services. That procedure is covered in Section 3 of this appendix.

d. The AAM is used for evaluating the potential interference to ILS/VOR from FM broadcast stations. The AAM negates tedious calculation after all parameters have been inputted.

18. OE CASE EVALUATION PROCEDURE . A work sheet is a very handy guide. It assures that all needed functions are accomplished and describes what conditions led to the concur/non-concur decision. See figure 15 for a practical worksheet. To start with, gather the heading information from the Form 7460-1. It is needed in working the AAM. Use the antenna AMSL height from 5C of that form, unless the PROP supplies an antenna drawing with dimensions so that the RCAMSL of the transmitting antenna is specified. Use RCAMSL if it is available.

Page 23 6050.32B Appendix 1, Section 2 – continued 11/17/05 FIGURE 15. SAMPLE OE CASE WORKSHEET FOR FM Page 24 11/17/05 Appendix 1, Section 2 - continued 6050.32B a. Task 1 . Use the CIRCLE program to obtain a circle search of all FAA and military COMM facilities within 30 nmi of the PROP's location. When the CIRCLE report prints out, look first for the lowest/closest FAA or military VHF frequency. If none is found, then look for the first UHF. In the rare event that no FAA/military ground VHF/UHF COMM is found, then skip Task 2, below, and go on directly to Task 3. Normally there will be a site. Complete the key in front of the appropriate entry for this function in the worksheet. A sample printout is shown in figure 16.

b. Task 2. Determine the actual levels , using the GROUND.WRK1 File. Enter the data from the worksheet and antenna data from the graphs within the program. When completed, type "P" and the form will print out on your printer. A sample printout is shown in figure 17. Notice the last two lines on the page. If the calculated values are less than the two maximum permissible values shown, this part of the study is completed.

Note that they are negative values, so a lesser value of signal is a greater negative number. Mark the first two keys of the result on the worksheet. If either exceeds, complete that portion of the sub-status statements on the work sheet and be guided accordingly for the final recommendation as to concur/non-concur or concur with comment.

c. Task 3. Run the AAM program . Instructions are contained in the User's Manual and Technical Reference to the Airspace Analysis Model .

Page 25 6050.32B Appendix 1, Section 2 – continued 11/17/05 FIGURE 16. SAMPLE PC CIRCLE REPORT Page 26 11/17/05 Appendix 1, Section 2 - continued 6050.32B FIGURE 17. SAMPLE GROUND.WK1 REPORT Page 27 6050.32B Appendix 1, Section 2 – continued 11/17/05 19. EXAMPLE OF AAM PROGRAM FOR FM/ILS a. The following illustrates a typical OE case study. For the example, FM station KHTN is requesting to move its facilities to another location. Both the present and new location of KHTN must be earmarked as "PROP'S" by placing a "1" in the appropriate column for KHTN.

b. Using the parameters in figures 9 and 15 , the AAM program will produce a plot of the ILSs that need to be studied (see figure 18). Although all 5 ILSs within 30 nmi shown on the plot must be checked, only MCE is used for this example. Even though the AAM may prompt for the back courses, the Terminal Procedures manual should be consulted to verify whether the back course must be evaluated.

c. After the FM and VOR database has been edited and the AAM has run this phase, it produces the RFI.PRT which indicates RFI for both the PROP and the present station. See figure 19. Note in the summary at the end of the report that a greater number of IM points exists for KTHN than for the PROP.

d. Figures 20 and 21 are the horizontal printouts of the predicted RFI. The numbers 1 through 9 and letters a through d indicate the intensity of the predicted RFI. The higher the number (or letter), the higher the intensity.

Their locations within the FPSV indicate the predicted RFI location and altitude. Because of the small font size of the numerals or letters, a dot-matrix printer or low dots-per-inch (dpi) printer may not resolve them, but show only dots. No letters or numerals in the printout would indicate no RFI is predicted. The bold lines in these horizontal studies printout pages indicate the altitude "slice" studied, in this case, the default, the bottom of the FPSV.

e. Figures 22 and 23 are the vertical printouts of the predicted RFI. The numbers and letters represent the same information as in figures 20 and 21. The bold lines in these vertical studies printout pages indicate the azimuth of the vertical "slice."

f. Based on the MCE analysis data , a PROP's move to the requested location would reduce the potential RFI to MCE (front course), thus would be advantageous to FAA. The action would be concur with conditional statement . That statement would indicate that the move would be satisfactory by reducing the RFI potential.

However, if there is increased RFI, the PROP must take steps to remedy the problem at the onset.

g. The GROUND.WK1 printout showed that the in-band level of -104 dBm would be exceeded, so an additional concur with comment is appropriate which advises the PROP that the spurious emissions must be additionally attenuated to assure the -104 dBm level is not exceeded at the Merced RCF.

Page 28 11/17/05 Appendix 1, Section 2 - continued 6050.32B FIGURE 18. AAM PROGRAM SAMPLE SEARCH PLOT Page 29 6050.32B Appendix 1, Section 2 – continued 11/17/05 FIGURE 19a. AAM PROGRAM SAMPLE RFI.PRT PRINTOUT Page 30 11/17/05 Appendix 1, Section 2 - continued 6050.32B FIGURE 19b. AAM SAMPLE RFI.PRT PRINTOUT (Continued) Page 31 6050.32B Appendix 1, Section 2 – continued 11/17/05 FIGURE 20. AAM SAMPLE PLOT OF PREDICTED RFI - HORIZONTAL - KHTN Page 32 11/17/05 Appendix 1, Section 2 - continued 6050.32B FIGURE 21. AAM SAMPLE PLOT OF PREDICTED RFI - HORIZONTAL - PROP Page 33 6050.32B Appendix 1, Section 2 – continued 11/17/05 FIGURE 22. AAM SAMPLE PLOT OF PREDICTED RFI - VERTICAL - KHTN Page 34 11/17/05 Appendix 1, Section 2 - continued 6050.32B FIGURE 23. AAM SAMPLE PLOT OF PREDICTED RFI - VERTICAL - PROP FIGURES 24. thru 30. RESERVED 20.-24. RESERVED Page 35 (thru 40)

11/17/05 Appendix 1 - continued 6050.32B SECTION 3. ENGINEERING PROCEDURES FOR OBSTRUCTION EVALUATION (OE) CASES FOR NON-FM BROADCAST 25. STATUS. It is recognized that at the time of this revision of Order 6050.32, a rulemaking was underway which was expected to substantially change this section, with respect to the facilities to be addressed and the procedures to be used. However, since the final results of the rulemaking were not known at the time of this revision, the following procedures are still in effect. Technical Operations ATC Spectrum Engineering Services will advise the FMOs when the final changes have been made and of the changes related to this section.

26. NON-FM BC STUDY PROCEDURES .

a. The initial step is the CIRCLE REPORT . The search radius varies with the service being investigated.

The radii are: (1) Cellular telephone - 2 nmi (2) Land mobile/microwave - 12 nmi (3) AM Broadcast - 3 nmi (4) TV Broadcast - 10 nmi (5) Other - as appropriate for the service b. After the report has been printed , review it for FAA facilities within the radii shown in subparagraph a.

above. The following are the parameters for concur/non-concur statements.

c. Cellular (1) If source is greater than 1 nmi, concur.

(2) If source is equal to or less than 1 nmi, check in/out-of-band levels.

(3) If in-band/out-of-band levels are exceeded , proceed per subparagraph i.

d. AM Broadcast (1) If source is greater than 1 nmi, concur.

(2) If source is equal to or less than 1 nmi, check in/out-of-band levels.

(3) If in-band/out-of-band levels are exceeded , proceed per subparagraph i.

e. TV Broadcast (1) If source is greater than 10 nmi, concur.

(2) If source is equal to or less than 10 nmi, check in/out-of-band levels.

(3) If in-band/out-of-band levels are exceeded , then: Page 41 6050.32B Appendix 1, Section 3 – continued 11/17/05 (a) If VHF-TV , issue a determination of no hazard with conditional statement.

(b) If UHF-TV and the problem cannot be corrected by reducing power, lowering the antenna or moving the site, then issue a determination of no hazard with conditional statement.

f. Microwave (1) Not in government band , concur.

(2) In government band , check in/out-of-band levels.

(3) If in-band/out-of-band levels are exceeded , proceed per subparagraph i.

g. Land mobile (1) If source is greater than 12 nmi, concur (2) If source is equal to or less than 12 nmi, check in/out-of-band levels (a) If the out-of-band level is between -4 to -30 dBm, run the INTERMOD program for 118-137 MHz (COMM receivers) to determine whether there will be IM's which will overlap at the receiver site.

(b) If there is no overlap , concur.

(c) If there is overlap , non-concur.

(d) If the level is ≥ -4 dBm , non-concur.

h. Band levels (1) In-band spurious level < -104 dBm - concur (2) In-band spurious level ≥ -104 dBm - concur with comment (3) Out-of-band radiation level < -4 dBm - concur (4) Out-of-band radiation level ≥ -4 dBm - non-concur i. Procedure for AM, cellular and microwave . Refer to Chapter 8, paragraph 807 of this order for detailed procedures involving AM broadcast and non-broadcast facilities.

27. A NON-FM BC EXAMPLE.

a. The example is a 60 W Land Mobile transmitter on 155.25 MHz to be located about 200' from an FAA ATCT COMM facility. See sample work sheet figure 31.

(1) The GROUND.WK1 program was run, which produced in-band radiation level of -65.7 dBm and out-of-band level of -8.6 dBm. This would require a "concur with comment" letter that essentially states FAA concurrence with the installation provided sufficient spurious suppression is installed to assure a level < -104 dBm at the FAA band 118-137 MHz. See figure 32.

Page 42 11/17/05 Appendix 1, Section 3 - continued 6050.32B FIGURE 31. SAMPLE NON-FM WORK SHEET Page 43 6050.32B Appendix 1, Section 3 – continued 11/17/05 32. PARAGRAPH 26 a. (1) EXAMPLE GROUND.WK1 PRINTOUT Page 44 11/17/05 Appendix 1, Section 3 - continued 6050.32B (2) The -8.6 dBm level was below the -4 dBm maximum level. However, the possibility of -10 dBm and -30 dBm IM levels overlapping at the site needs to be checked.

(3) The IM program was run . The PROP frequency of 155.25 MHz was added in the edit mode before it was run. See figure 33 for the configuration.

FIGURE 33. PARAGRAPH 26 a. (3) EXAMPLE OF IM PROGRAM CONFIGURATION Source Type Invol Cons Radius nmi GMF TX yes yes 12 PND TX yes yes 12 AM TX yes yes 2 FM TX yes yes 30 TV TX yes yes 10 CAN TX no no 2 Path/Filename GMF \GMF\ PND \PND\ AM \FCC\AM\ FM \FCC\FM\ TV \FCC\TV\ CAN \CAN\ (4) In this case , the IM complete report was blank, indicating there were no IMs within the selected range. See figure 34.

FIGURE 34. PARAGRAPH 26 a. (4) EXAMPLE OF IM PROGRAM PRINTOUT Page 45 6050.32B Appendix 1, Section 3 – continued 11/17/05 (5) Had there been IMs, the CIRCLE report would have to have been run. An area of one-half mile radius would need to be checked. If any IM overlaps occurred in this area, a Venn diagram would be required to determine whether the -10 dBm and -30 dBm contours of the subject sources would overlap the site. In this unlikely event, a "non-concur" would have to be given.

b. If the exact distance is known , the actual loss can be calculated from the modified free space formula found in paragraph 10 b., section 1, of this appendix. Using this formula, the actual loss in dB can be determined.

With the PROP EIRP in dBm, the loss can be subtracted and the result in dBm can be compared to the -10 dBm and the -30 dBm limits for ground receivers. This will quickly determine whether the PROP's two critical contours would overlap with any other nearby FAA or broadcast critical contours which would predict RFI at the FAA ground site.

Page 46 6050.32B Appendix 2 – continued 11/17/05 1. VHF/UHF FREQUENCY ENGINEERING . Frequencies available to the FMO for engineering VHF assignment are given in figure 1 and UHF ATC frequencies are found in the latest version of the 225-400 MHz channel plan. VHF is used normally for communication with civil aircraft and a limited number of military aircraft. UHF is used only for communication with military aircraft. Military non-ATC communications shall not use VHF ATC frequencies. Military tactical and training (TAC and training) operations and Research, Test, Development, and Evaluation (RTDE) shall not use UHF ATC frequencies.

a. In en route functions , a VHF and a UHF frequency are normally paired. In addition, a tactical UHF frequency may be assigned to an en route sector to support military operations.

b. In terminal functions , a VHF and a UHF are paired for only some functions.

2. FPSV .

a. COMM frequencies are engineered for distinct volumes of airspace and are guaranteed to be free from a preset level of interference from an undesired source. Each specific function has its own FPSV. Some are cylinders, while others are odd geometric solids. These odd shapes are normally required for en route ATC functions. All FPSVs are valid only within Radio Line Of Sight (RLOS). Refer to paragraph 4 for details.

b. Cylindrical service volumes (CSV) are defined as radii in nmi usually centered on the facility, with the maximum altitude of the cylinder defined in feet. These parameters are defined for the various ATC functions in paragraph 2d, below. A sketch of a cylindrical service volume is shown in figure 2.

c. Tailored or "multipoint" service volumes (TSV) are unique shapes designed to afford necessary coverage within a designed interference-free protection level. The geometric center of the tailored service is the center point for the radius that is the distance to the farthest point of the TSV. A sketch of a typical TSV is also shown in figure 2. The geometric center and radius can be found by using the center point and radius of the smallest circle that will cover all of the TSV.

FIGURE 2. FPSVs Page 2 11/17/05 Appendix 2 - continued 6050.32B d. FPSV graphic representations in this manual are drawn for illustrative purposes. They are not drawn to scale, but rather to a standard of clarity. An example of High Altitude En Route and Local Control to scale and as normally drawn is shown in figure 3. In addition, all FPSVs are drawn planar and do not include the curvature of the earth, as also shown in figure 3.

FIGURE 3. HIGH ALTITUDE ENROUTE AND LOCAL CONTROL FPSVs TO APPROXIMATE SCALE AND AS NORMALLY SHOWN PICTORIALLY (1) ARTCC . Frequency assignments for ARTCC facilities are located at Remote Control Air/Ground (RCAG) sites. These RCAGs are connected to the ARTCC by telephone lines, microwave or other radio links.

They are divided into categories of Low Altitude En Route, High Altitude En Route and Super High Altitude En Route. They normally have tailored or multipoint service volumes, the maximum altitude and radius usually not exceeding the values shown in figure 4. Under no circumstances will an FPSV be approved with a radius greater than the RLOS distance.

FIGURE 4. EXAMPLE OF EN ROUTE DIMENSIONS Service Altitude (feet) Radius nmi Super High En Route >45,000' AMSL 150 High Enroute 45,000' AMSL 150 Low En Route 24,000' AMSL 75 Page 3 6050.32B Appendix 2 – continued 11/17/05 (2) ATCT . These frequencies are usually found in the tower itself or at an RCF on or near the airport it serves. The service volumes normally have cylindrical shapes; the radius and flight levels are shown in figure 5.

If there is uncertainty as to an appropriate FPSV for terminal operations, the letter of agreement between the terminal facility and the center will specify the delegated airspace. FPSVs should not exceed the delegated air space. Under no circumstances will an FPSV be approved with a radius greater than the RLOS distance.

FIGURE 5. TYPICAL TERMINAL FPSV DIMENSIONS SERVICE SMALL TYPICAL LARGE Ground Control -- 100' & 3 nmi -- Clearance Delivery -- 100' & 3 nmi -- Local Control 2,500' & 10 nmi 5,000' & 15 nmi 10,000' & 30 nmi Approach/Departure Arrival 7,500' & 30 nmi 10,000' & 45 nmi 24,000' & 55 nmi Final 3,000' & 15 nmi 4,000' & 20 nmi 5,000' & 25 nmi Satellite Airport 3,000' & 20 nmi -- 5,000' & 30 nmi Helicopter 2,500' & 10 nmi 5,000' & 15 nmi 5,000' & 30 nmi GCA/PAR/SFA (Including pattern) 2,500' & 10 nmi 3,000' & 15 nmi 5,000' & 20 nmi AWOS/ASOS 5,000' & 15 nmi -- 10,000' & 25 nmi ATIS Match or slightly exceed Arrival 25,000' & 60 nmi Departure ATIS -- 100' & 3 nmi -- (3) Flight Service Station (FSS) . FSS frequencies, including low altitude En Route Flight Advisory Service (EFAS), are located either at the FSS or at a nearby RCF. High altitude EFAS channels are assigned on ATC channels. Multiple high altitude EFAS facilities serving the same ARTCC must share a single frequency.

FSS frequencies are protected as much as is possible considering that many sites geographically within RLOS use the same frequency. This is normally accomplished by separating FSS cochannel assignments by at least 100 nmi, where possible.

e. Noncovered Services . The following VHF aeronautical frequency services are not covered by this appendix, since all are controlled and authorized by FCC. Refer to FCC Part 87 Rules and Regulations for details and frequencies.

(1) Aviation Support . Flying schools, soaring, ballooning, etc.

(2) Aeronautical Advisory (UNICOM) . Fixed base operators.

(3) MULTICOM. A special use UNICOM.

(4) Flight Test . Manufacturer's use for flight tests of aircraft or equipment.

Page 4 11/17/05 Appendix 2 - continued 6050.32B (5) Operational Control . Airlines' own use.

(6) Search And Rescue . As name implies.

(7) Airport Utility . Non-FAA vehicles on airports.

3. ATC ASSIGNMENT CRITERIA . There are basic criteria for engineering a COMM frequency assignment.

a. Sufficient signal must be provided at the aircraft's receiver to ensure satisfactory performance at a point in the FPSV furthest from the ground transmitter. ICAO Standards and Recommended Practices (SARPs) recommends a signal-in-space field strength of 75 μv/m (-109 dBW /m ), which translates to –82.5 dBm, assuming a 0 dB aircraft antenna gain (ICAO Annex 10, Volume 3, Part 2, Chapter 2). RTCA Minimum Operational Performance Standards (MOPS) specifies that the input to the aircraft receiver should be 10 μv (across a 50 ohm impedance), or –87 dBm (RTCA DO-186a). Therefore, approximately 4.5 dB of margin is provided for the losses between the input to the antenna and the input to the receiver. Such losses include antenna gains of less than 0 dB and cabling losses between the antenna and the input to the receiver. A series of curves for VHF and UHF limits of coverage, for a receiver input power of –87 dBm, are found in figures 13 through 24 of this appendix.

b. Protection criteria. ICAO recommends 20 dB desired to undesired (D/U) frequency assignment protection criteria, but has recognized that in areas with severe frequency assignment congestion, such as the Continental U.S., a lesser but safe value of 14 dB D/U can be applied. The 14 dB D/U is applicable for all ATC functions with station class of FA, FAB, FAC and FLU. In addition, a maximum of -4 dBm out-of-band and a maximum of -104 dBm in-band limit protections are provided from external signals.

c. Transmitter power . Existing policy on transmitter output power is to use 2.5W for AWOS, ASOS and Automated Remote Radio Access System (ARRAS) operations, and to not exceed 10 W for all other operations.

The need for higher power must be justified in the FMO’s application for frequency approval .

d. ATIS, AWOS and ASOS frequency assignment priorities are described in paragraphs 904 and 905 of this order.

4. RLOS . In space, radio signals tend to propagate in a straight line. Near large bodies they tend to "bend" toward the body. In the case of the earth, a sufficiently close approximation of the "effective radio horizon" can be obtained by using the formula in subparagraph a. below which assumes the earth to be 4/3 its actual radius, hence the "4/3 radius" phenomenon. The formula approximation assumes a "smooth" earth, since intervening terrain will stop or attenuate VHF and higher signals.

Page 5 6050.32B Appendix 2 – continued 11/17/05 a. At any given altitude , a transmitted signal will travel only a specific earth distance before it becomes tangent to the earth's radio horizon. Distances beyond the tangency do not ordinarily receive any VHF or higher signals, except under anomalous propagation. Treatises on RLOS can be found in engineering manuals, such as the ITT REFERENCE DATA FOR RADIO ENGINEERS , under radio wave propagation. The formula for RLOS is: h miles statute RLOS 2 ) ( = Where: h = height in feet, AMSL.

+++++++++++++++++++++++++++++++++++++ h h nmi RLOS 23 . 1 2 87 . 0 ) ( = = Where: h = height in feet, AMSL.

b. Where two elevated sites are involved , the formula is: 2 23 . 1 1 23 . 1 ) ( h h nmi RLOS + = Where h1 and h2 are respective point altitudes, in feet, AMSL.

c. A sketch of 4/3 earth radius radio coverage is found in figure 6.

FIGURE 6. COMPARISON OF DISTANCE TO HORIZON FROM THE SAME ALTITUDE BETWEEN ACTUAL AND HYPOTHETICAL 4/3 EARTH RADIUS Page 6 11/17/05 Appendix 2 - continued 6050.32B 5. INTERSITE FREQUENCY ENGINEERING PROCEDURES . These procedures require the determination that at the worst-case, an aircraft will receive a signal from the desired facility 14 dB stronger than from a cochannel undesired facility, that is, D/U = 14 dB. (Adjacent channel will be covered later in this discussion). The determination is based on the free-space loss formula (L ): fs L (dB) = 37.8 + 20 log f + 20 log d fs NOTE: L formula is valid only for distances less than RLOS where: fs f = frequency in MHz d = distance in nmi a. Note that a signal level only decreases by 6 dB when the distance is doubled, since the signal voltage (thus current) ratio is only halved at twice the distance (i.e., 20 log (2) = 6dB).

b. Note that the loss constant and the 20 log f variable are fixed when dealing with a cochannel study.

Only the 20 log d varies.

c. Since the 14 dB D/U is determined by the ratio of the distances of undesired to desired sources, d /d , U D from the critical point, only the 20 log d need be used to determine required separation (see figure 7). The signal strength D/U is inversely proportional to the distance ratio (DR) from d to d . The equation becomes U D D/U = 20 log (d /d ) ≥ 14 dB.

U D d. The critical point is that point on the edge of the FPSV where an aircraft is simultaneously furthest from the desired facility and closest to edge of a cochannel or adjacent channel FPSV, where another aircraft would be the "undesired signal" D U.

FIGURE 7. COCHANNEL CONFIGURATION FOR UNDESIRED/DESIRED DISTANCE RATIO Page 7 6050.32B Appendix 2 – continued 11/17/05 e. In figure 7 , to achieve a difference of 14 dB at the critical point, the DR, d /d , should be 5 or greater or U D the antilog of 14 divided by 20.

20 log d /d = 14 U D log d /d = 14/20 = 0.7 U D antilog 0.7 = 5.01 NOTE: When d is beyond RLOS, protection will be greater than 14 dB .

U f. To complete the analysis , the configuration must now be analyzed with the desired and undesired stations reversed. For the systems to operate properly without interference, both configurations must meet the cochannel criteria.

6. INTERSITE COCHANNEL ANALYSIS BY THE TABLE METHOD . If only cylindrical standard FPSVs are considered, the figure 8 may be used to assure the 14 dB D/U ratio.

FIGURE 8. MILEAGE SEPARATION TABLES FOR USUAL FPSVs FACILITY SERVICE ACFT TO ACFT TOTAL TYPE RADIUS SEPARATION REQUIRED (Desired) (Critical Points) High Altitude 150 + 525* 675 + R Approach/Departure 60 + 300 360 + R Local 30 + 150 180 + R GCA/PAR/SFA 15 + 75 90 + R N ote: "R" is the service radius in nmi of the competing facility.

* Separation modified by RLOS.

7. ADJACENT CHANNEL CONSIDERATIONS . Adjacent-channel signals 25 kHz away are suppressed approximately 60 dB by the bandpass characteristics of the 720 channel receiver. A +14 dB D/U ratio is required on-channel, leaving a net ratio of -46 dB, the value that an adjacent channel signal must not exceed on-channel to maintain the +14 dB D/U ratio. Empirical tests have shown that between 0.5 and 0.6 nmi separation between the undesired signal source and the desired critical point will provide this protection. Since aircraft operating in a difference sector/service may also be separated by 0.5-0.6 nmi in altitude, vertical adjacent channel separation may also be considered. A conservative vertical separation of 7000' has been included in the automated spectrum assignment program. The use of vertical adjacent channel separation requires the proper coding of the lower flight level in high and super high sector assignments. The use of the conservative vertical separation value of 7000' in the model is provided to ensure that adequate adjacent channel separation will be provided while experience is gained with using vertical adjacent channel separation. Figure 9 graphically illustrates vertical adjacent channel separation.

Page 8 11/17/05 Appendix 2 - continued 6050.32B a. For en route functions , AT procedures require aircraft to be separated 3 nmi, so that an adjacent-channel aircraft will never be closer than the minimum distance required.

b. For terminal functions , aircraft can be much closer, so that a small worst-case protection is required.

Any separation greater than 0.6 nmi between edges of adjacent channel FPSVs will provide adequate protection; see the example in figure 10.

c. 2nd adjacent channel assignments need no consideration in intersite analysis.

FIGURE 9. ADJACENT CHANNEL VERTICAL SEPARATION Page 9 6050.32B Appendix 2 – continued 11/17/05 FIGURE 10. 1ST ADJACENT CHANNEL SEPARATION REQUIRED 8. INTERSITE COCHANNEL ANALYSIS .

a. To determine the DR of any critical point, first determine if d is beyond RLOS using the formula in U paragraph 4b. The d for this RLOS criterion is the shortest distance between the two cochannel FPSVs. If d is U U beyond RLOS, the DR will be greater than 14 dB for both FPSVs. When both cochannel FPSVs are cylindrical and the transmitters are in the center of the FPSVs, the worst- case DR is where the d is the shortest distance U between FPSVs and d is the cylinder radius. The configuration is shown in figure 8 and the calculation of DR is D shown in paragraph 5d, above.

b. When the transmitter is not at the center of the FPSV or the FPSV is tailored and not cylindrical, the worst-case DR can occur when d is not a minimum and d can be the maximum distance between the transmitter U D and the perimeter of the FPSV. An example of a calculation for a noncylindrical FPSV is demonstrated in figures 11 and 12. The d for the worst-case DR for the cylindrical FPSV1 is the minimum distance between FPSVs U which is shown as 226 nmi. The worst-case DR would then be 226 nmi divided by the 30 nmi radius or 7.53.

FPSV1 thus passes the DR criteria as the DR is greater than 5. The d for the worst case DR for the U noncylindrical FPSV2 occurs where the d is about 330 nmi. With d being 65 nmi, the worst case DR for U D FPSV2 would be 330 ÷ 65 or 5.08. FPSV2 passes the DR criteria. It is important to consider that all points on a TSV must be checked when using the DR criteria.

c. In this example , a common channel frequency can be used. If either FPSV1 or FPSV2 fails the DR =  5 or 14 dB criterion, then the same frequency cannot be use for both FPSVs. Since the new facility FPSV2 is not a cylindrical FPSV, the worst-case situation is not an "in-line" function. The worst-case DR must be determined by direct map measurement as shown in figure 12. FAA’s automatic A/G computer model does the calculation for cylinders or equivalent cylinders with off-center transmitter locations. (NOTE: The AFM uses actual TSV points Page 10 11/17/05 Appendix 2 - continued 6050.32B to calculate DR if the TSV option is selected.) An equivalent cylinder to a TSV can be overprotected by the computer model and should be further checked by direct map measurement if it fails the computer model's DR.

FIGURE 11. COCHANNEL ANALYSIS BY CALCULATION FIGURE 12. COMPARISON OF D/U AND DISTANCE BETWEEN FACILITIES WITH ONE TAILORED SERVICE VOLUME 9. COSITE INTERFERENCE CONSIDERATIONS . Cosite interference results from the interaction of transmitters and receivers in close proximity. Usually this means in the same building, or in adjacent buildings up to one mile away for 50 watt transmitters and 2,000' away for 10 watt transmitters, but in the case of high power FM and TV broadcast stations, it can mean several miles away. The appendix contains a discussion of interference involving commercial broadcast stations.

a. Adjacent sources . In FAA cosite installations, the standard is a minimum separation of 500 kHz for VHF and 1 MHz for UHF when there is an 8' minimum separation between transmit antennas and an 80 minimum separation between transmit and receive antennas.

b. Harmonics . These come from two general sources.

Page 11 6050.32B Appendix 2 – continued 11/17/05 (1) FAA equipment . This is usually the second or third harmonic of VHF transmitters afflicting UHF receivers. It is generally quite difficult to operate a receiver on a direct harmonic of a transmitter cosite, even with transmitter band-pass filtering. Direct harmonic operation shall be avoided cosite.

(2) External sources . These can come from a variety of sources, FM and TV aural and video spurious emissions and harmonics in VHF and UHF, Land Mobile 35-50 MHz spurious emissions and harmonics in VHF, CB and Amateur in both VHF and UHF. The only ones that can be planned against are the FM and TV harmonics.

c. Spurious emission . Any frequency put out by a transmitter which is not the fundamental frequency is spurious. These are normally harmonics, which are easy to plan against, but also there are multiples and odd multiples of crystal oscillators or synthesizer mixers. Receivers also are subject to local oscillator radiation which can affect other receivers in the same rack or room. Principally, "image" interference to receivers, reception of a signal which mixes with the local oscillator to produce the receiver's IF, should be avoided. The FMO should be familiar with IFs used in receivers in a given site so that direct image reception can be avoided.

d. Intermod . This is the most common source of cosite interference. It results from the mixing of two or more cosite transmitters which, when added or subtracted from one another in some sequence, produces a resultant frequency equal to one being received elsewhere at the site. Discussion of intermod calculations will be found in paragraph 1405a(3)(d) of this order. FAA policy is to not assign frequencies having third order IM prediction from nearby possible sources..

e. Image interference . Interference can be generated by nearby strong signals which produce the IF by mixing with the LO in the receiver. This problem normally occurs only with nearby and/or very strong signal sources. See paragraph 1405a(3)(e) for details.

10. LIMITS OF COVERAGE CHARTS .

a. A sufficient signal level is required at the aircraft anywhere within the FPSV as described in paragraph 3 of this appendix. A major factor in the coverage is the height of the antenna above effective ground and the roughness of the terrain surrounding the antenna location. Charts showing coverage at the two standard powers of 10 W and 50 W at different antenna heights are shown in figures 13-24.

b. The Brewster Angle is the term applied to the effect of lobing of the theoretical "doughnut" radiation pattern around a vertical antenna in space. In practice, most FAA RCF antennas are ground planes, and have a modified radiation pattern just from the plane effect. In addition, there are direct rays from the antenna to the aircraft and rays which are received as a result of reflection from the ground.

c. Lobing is caused by the difference in phase of the transmitted signal arriving at the receiving point as a combination of direct rays and reflected rays. Depending on frequency and antenna height above effective ground, these rays can combine to produce an out-of-phase condition resulting in a very low level of signal, or an in-phase condition where the signal level is enhanced. These conditions vary with altitude, distance, power, frequency and ground antenna height above effective ground.

d. The charts shown in figures 13-24 are intended to indicate the volumes of airspace within which a proposed FPSV or ESV will be provided with the required minimum signal of -87 dBm at the aircraft receiver (RTCA MOPS, DO-186a; see paragraph 3a above). All areas to the left of the respective curves are expected to have the minimum required signal level at any azimuth. However, there are definitely inaccuracies in some areas, particularly at the higher AGL antennas due to a discontinuity of signal levels at some altitudes at some distances.

Page 12 11/17/05 Appendix 2 - continued 6050.32B FIGURE 13. LIMITS OF COVERAGE - VHF - ANTENNA HEIGHT = 10' Page 13 6050.32B Appendix 2 – continued 11/17/05 FIGURE 14. LIMITS OF COVERAGE - VHF - ANTENNA HEIGHT = 25' Page 14 11/17/05 Appendix 2 - continued 6050.32B FIGURE 15. LIMITS OF COVERAGE - VHF - ANTENNA HEIGHT = 50' Page 15 6050.32B Appendix 2 – continued 11/17/05 FIGURE 16. LIMITS OF COVERAGE - VHF - ANTENNA HEIGHT = 75' Page 16 11/17/05 Appendix 2 - continued 6050.32B FIGURE 17. LIMITS OF COVERAGE - VHF - ANTENNA HEIGHT = 100' Page 17 6050.32B Appendix 2 – continued 11/17/05 FIGURE 18. LIMITS OF COVERAGE - VHF - ANTENNA HEIGHT = 150' Page 18 11/17/05 Appendix 2 - continued 6050.32B FIGURE 19. LIMITS OF COVERAGE - UHF - ANTENNA HEIGHT = 10' Page 19 6050.32B Appendix 2 – continued 11/17/05 FIGURE 20. LIMITS OF COVERAGE - UHF - ANTENNA HEIGHT = 20' Page 20 11/17/05 Appendix 2 - continued 6050.32B FIGURE 21. LIMITS OF COVERAGE - UHF - ANTENNA HEIGHT = 30' Page 21 6050.32B Appendix 2 – continued 11/17/05 FIGURE 22. LIMITS OF COVERAGE - UHF - ANTENNA HEIGHT = 40' Page 22 11/17/05 Appendix 2 - continued 6050.32B FIGURE 23. LIMITS OF COVERAGE - UHF - ANTENNA HEIGHT 50' Page 23 6050.32B Appendix 2 – continued 11/17/05 FIGURE 24. LIMITS OF COVERAGE - UHF - ANTENNA HEIGHT = 75' Page 24

11/17/05 6050.32B

APPENDIX 3. NAVAID FREQUENCY ENGINEERING

DATA AND PROCEDURES

SECTION 1 - FREQUENCY/CHANNELIZATION CHART

FIGURE 1a. CHANNEL AND FREQUENCY PAIRING WITH DME PULSE TIME/CODES

DME AIRBORNE DME GROUND INTERROGATE REPLY DME MLS NORMAL DME/P CHN -------------FREQUENCY---MHz---------- CHN DME IA FA DME PC NO. LOC GS VOR MLS NO. FREQ μs μs μs FREQ μs 1X - - - - - 1025 12 -- -- 962 12 1Y - - - - - 1025 36 -- -- 1088 30 2X - - - - - 1026 12 -- -- 963 12 2Y - - - - - 1026 36 -- -- 1089 30 3X - - - - - 1027 12 -- -- 964 12 3Y - - - - - 1027 36 -- -- 1090 30 4X - - - - - 1028 12 -- -- 965 12 4Y - - - - - 1028 36 -- -- 1091 30 5X - - - - - 1029 12 -- -- 966 12 5Y - - - - - 1029 36 -- -- 1092 30 6X - - - - - 1030 12 -- -- 967 12 6Y - - - - - 1030 36 -- -- 1093 30 7X - - - - - 1031 12 -- -- 968 12 7Y - - - - - 1031 36 -- -- 1094 30 8X - - - - - 1032 12 -- -- 969 12 8Y - - - - - 1032 36 -- -- 1095 30 9X - - - - - 1033 12 -- -- 970 12 9Y - - - - - 1033 36 -- -- 1096 30 10X - - - - - 1034 12 -- -- 971 12 10Y - - - - - 1034 36 -- -- 1097 30 11X - - - - - 1035 12 -- -- 972 12 11Y - - - - - 1035 36 -- -- 1098 30 12X - - - - - 1036 12 -- -- 973 12 12Y - - - - - 1036 36 -- -- 1099 30 13X - - - - - 1037 12 -- -- 974 12 13Y - - - - - 1037 36 -- -- 1100 30 14X - - - - - 1038 12 -- -- 975 12 14Y - - - - - 1038 36 -- -- 1101 30 15X - - - - - 1039 12 -- -- 976 12 15Y - - - - - 1039 36 -- -- 1102 30 16X - - - - - 1040 12 -- -- 977 12 16Y - - - - - 1040 36 -- -- 1103 30 17X - - 108.00 - 1041 12 -- -- 978 12 17Y - - 108.05 5043.0 540 1041 36 36 42 1104 30 18X 108.10 334.70 - 5031.0 500 1042 12 12 18 979 12 18Y 108.15 334.55 - 5043.6 542 1042 36 36 42 1105 30 19X - - 108.20 - - 1043 12 -- -- 980 12 19Y - - 108.25 5044.2 544 1043 36 36 42 1106 30 20X 108.30 334.10 - 5031.6 502 1044 12 12 18 981 12 20Y 108.35 333.95 - 5044.8 546 1044 36 36 42 1107 30

Page 1

6050.32B Appendix 3, Section 1 – continued 11/17/05

FIGURE 1b. CHANNEL AND FREQUENCY PAIRING WITH DME PULSE TIME/CODES

(CONTINUED)

DME AIRBORNE DME GROUND INTERROGATE REPLY DME MLS NORMAL DME/P CHN -------------FREQUENCY---MHz---------- CHN DME IA FA DME PC NO. LOC GS VOR MLS NO. FREQ μs μs μs FREQ μs 21X - - 108.40 - - 1045 12 -- -- 982 12 21Y - - 108.45 5045.4 548 1045 36 36 42 1108 30 22X 108.50 329.90 - 5032.2 504 1046 12 12 18 983 12 22Y 108.55 329.75 - 5046.0 550 1046 36 36 42 1109 30 23X - - 108.60 - - 1047 12 -- -- 984 12 23Y - - 108.65 5046.6 552 1047 36 36 42 1110 30 24X 108.70 330.50 - 5032.8 506 1048 12 12 18 985 12 24Y 108.75 330.35 - 5047.2 554 1048 36 36 42 1111 30 25X - - 108.80 - - 1049 12 -- -- 986 12 25Y - - 108.85 5047.8 556 1049 36 36 42 1112 30 26X 108.90 329.30 - 5033.4 508 1050 12 12 18 987 12 26Y 108.95 329.15 - 5048.4 558 1050 36 36 42 1113 30 27X - - 109.00 - - 1051 12 -- -- 988 12 27Y - - 109.05 5049.0 560 1051 36 36 42 1114 30 28X 109.10 331.40 - 5034.0 510 1052 12 12 18 989 12 28Y 109.15 331.25 - 5049.6 562 1052 36 36 42 1115 30 29X - - 109.20 - - 1053 12 -- -- 990 12 29Y - - 109.25 5050.2 564 1053 36 36 42 1116 30 30X 109.30 332.00 - 5034.6 512 1054 12 12 18 991 12 30Y 109.35 331.85 - 5050.8 566 1054 36 36 42 1117 30 31X - - 109.40 - - 1055 12 -- -- 992 12 31Y - - 109.45 5051.4 568 1055 36 36 42 1118 30 32X 109.50 332.60 - 5035.2 514 1056 12 12 18 993 12 32Y 109.55 332.45 - 5052.0 570 1056 36 36 42 1119 30 33X - - 109.60 - - 1057 12 -- -- 994 12 33Y - - 109.65 5052.6 572 1057 36 36 42 1120 30 34X 109.70 333.20 - 5035.8 516 1058 12 12 18 995 12 34Y 109.75 333.05 - 5053.2 574 1058 36 36 42 1121 30 35X - - 109.80 - - 1059 12 -- -- 996 12 35Y - - 109.85 5053.8 576 1059 36 36 42 1122 30 36X 109.90 333.80 - 5036.4 518 1060 12 12 18 997 12 36Y 109.95 333.65 - 5054.4 578 1060 36 36 42 1123 30 37X - - 110.00 - - 1061 12 -- -- 998 12 37Y - - 110.05 5055.0 580 1061 36 36 42 1124 30 38X 110.10 334.40 - 5037.0 520 1062 12 12 18 999 12 38Y 110.15 334.25 - 5055.6 582 1062 36 36 42 1125 30 39X - - 110.20 - - 1063 12 -- -- 1000 12 39Y - - 110.25 5056.2 584 1063 36 36 42 1126 30 40X 110.30 335.00 - 5037.6 522 1064 12 12 18 1001 12 40Y 110.35 334.85 - 5056.8 586 1064 36 36 42 1127 30

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11/17/05 Appendix 3, Section 1 - continued 6050.32B

FIGURE 1c. CHANNEL AND FREQUENCY PAIRING WITH DME PULSE TIME/CODES

(CONTINUED)

DME AIRBORNE DME GROUND INTERROGATE REPLY DME MLS NORMAL DME/P CHN -------------FREQUENCY---MHz---------- CHN DME IA FA DME PC NO. LOC GS VOR MLS NO. FREQ μs μs μs FREQ μs 41X - - 110.40 - - 1065 12 -- -- 1002 12 41Y - - 110.45 5057.4 588 1065 36 36 42 1128 30 42X 110.50 329.60 - 5038.2 524 1066 12 12 18 1003 12 42Y 110.55 329.45 - 5058.0 590 1066 36 36 42 1129 30 43X - - 110.60 - - 1067 12 -- -- 1004 12 43Y - - 110.65 5058.6 592 1067 36 36 42 1130 30 44X 110.70 330.20 - 5038.8 526 1068 12 12 18 1005 12 44Y 110.75 330.05 - 5059.2 594 1068 36 36 42 1131 30 45X - - 110.80 - - 1069 12 -- -- 1006 12 45Y - - 110.85 5059.8 596 1069 36 36 42 1132 30 46X 110.90 330.80 - 5039.4 528 1070 12 12 18 1007 12 46Y 110.95 330.65 - 5060.4 598 1070 36 36 42 1133 30 47X - - 111.00 - - 1071 12 -- -- 1008 12 47Y - - 111.05 5061.0 600 1071 36 36 42 1134 30 48X 111.10 331.70 - 5040.0 530 1072 12 12 18 1009 12 48Y 111.15 331.55 - 5061.6 602 1072 36 36 42 1135 30 49X - - 111.20 - - 1073 12 -- -- 1010 12 49Y - - 111.25 5062.2 604 1073 36 36 42 1136 30 50X 111.30 332.30 - 5040.6 532 1074 12 12 18 1011 12 50Y 111.35 332.15 - 5062.8 606 1074 36 36 42 1137 30 51X - - 111.40 - - 1075 12 -- -- 1012 12 51Y - - 111.45 5063.4 608 1075 36 36 42 1138 30 52X 111.50 332.90 - 5041.2 534 1076 12 12 18 1013 12 52Y 111.55 332.75 - 5064.0 610 1076 36 36 42 1139 30 53X - - 111.60 - - 1077 12 -- -- 1014 12 53Y - - 111.65 5064.6 612 1077 36 36 42 1140 30 54X 111.70 333.50 - 5041.8 536 1078 12 12 18 1015 12 54Y 111.75 333.35 - 5065.2 614 1078 36 36 42 1141 30 55X - - 111.80 - - 1079 12 -- -- 1016 12 55Y - - 111.85 5065.8 616 1079 36 36 42 1142 30 56X 111.90 331.10 - 5042.4 538 1080 12 12 18 1017 12 56Y 111.95 330.95 - 5066.4 618 1080 36 36 42 1143 30 57X - - 112.00 - - 1081 12 -- -- 1018 12 57Y - - 112.05 - - 1081 36 -- -- 1144 30 58X - - 112.10 - - 1082 12 -- -- 1019 12 58Y - - 112.15 - - 1082 36 -- -- 1145 30 59X - - 112.20 - - 1083 12 -- -- 1020 12 59Y - - 112.25 - - 1083 36 -- -- 1146 30 60X - - - - - 1084 12 -- -- 1021 12 60Y - - - - - 1084 36 -- -- 1147 30

Page 3

6050.32B Appendix 3, Section 1 – continued 11/17/05

FIGURE 1d. CHANNEL AND FREQUENCY PAIRING WITH DME PULSE TIME/CODES

(CONTINUED)

DME AIRBORNE DME GROUND INTERROGATE REPLY DME MLS NORMAL DME/P CHN -------------FREQUENCY---MHz---------- CHN DME IA FA DME PC NO. LOC GS VOR MLS NO. FREQ μs μs μs FREQ μs 61X - - - - - 1085 12 -- -- 1022 12 61Y - - - - - 1085 36 -- -- 1148 30 62X - - - - - 1086 12 -- -- 1023 12 62Y - - - - - 1086 36 -- -- 1149 30 63X - - - - - 1087 12 -- -- 1024 12 63Y - - - - - 1087 36 -- -- 1150 30 64X - - - - - 1088 12 -- -- 1151 12 64Y - - - - - 1088 36 -- -- 1025 30 65X - - - - - 1089 12 -- -- 1152 12 65Y - - - - - 1089 36 -- -- 1026 30 66X - - - - - 1090 12 -- -- 1153 12 66Y - - - - - 1090 36 -- -- 1027 30 67X - - - - - 1091 12 -- -- 1154 12 67Y - - - - - 1091 36 -- -- 1028 30 68X - - - - - 1092 12 -- -- 1155 12 68Y - - - - - 1092 36 -- -- 1029 30 69X - - - - - 1093 12 -- -- 1156 12 69Y - - - - - 1093 36 -- -- 1030 30 70X - - 112.30 - - 1094 12 -- -- 1157 12 70Y - - 112.35 - - 1094 36 -- -- 1031 30 71X - - 112.40 - - 1095 12 -- -- 1158 12 71Y - - 112.45 - - 1095 36 -- -- 1032 30 72X - - 112.50 - - 1096 12 -- -- 1159 12 72Y - - 112.55 - - 1096 36 -- -- 1033 30 73X - - 112.60 - - 1097 12 -- -- 1160 12 73Y - - 112.65 - - 1097 36 -- -- 1034 30 74X - - 112.70 - - 1098 12 -- -- 1161 12 74Y - - 112.75 - - 1098 36 -- -- 1035 30 75X - - 112.80 - - 1099 12 -- -- 1162 12 75Y - - 112.85 - - 1099 36 -- -- 1036 30 76X - - 112.90 - - 1100 12 -- -- 1163 12 76Y - - 112.95 - - 1100 36 -- -- 1037 30 77X - - 113.00 - - 1101 12 -- -- 1164 12 77Y - - 113.05 - - 1101 36 -- -- 1038 30 78X - - 113.10 - - 1102 12 -- -- 1165 12 78Y - - 113.15 - - 1102 36 -- -- 1039 30 79X - - 113.20 - - 1103 12 -- -- 1166 12 79Y - - 113.25 - - 1103 36 -- -- 1040 30 80X - - 113.30 - - 1104 12 -- -- 1167 12 80Y - - 113.35 5067.0 620 1104 36 36 42 1041 30

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11/17/05 Appendix 3, Section 1 - continued 6050.32B

FIGURE 1e. CHANNEL AND FREQUENCY PAIRING WITH DME PULSE TIME/CODES

(CONTINUED)

DME AIRBORNE DME GROUND INTERROGATE REPLY DME MLS NORMAL DME/P CHN -------------FREQUENCY---MHz---------- CHN DME IA FA DME PC NO. LOC GS VOR MLS NO. FREQ μs μs μs FREQ μs 81X - - 113.40 - - 1105 12 -- -- 1168 12 81Y - - 113.45 5067.6 622 1105 36 36 42 1042 30 82X - - 113.50 - - 1106 12 -- -- 1169 12 82Y - - 113.55 5068.2 624 1106 36 36 42 1043 30 83X - - 113.60 - - 1107 12 -- -- 1170 12 83Y - - 113.65 5068.8 626 1107 36 36 42 1044 30 84X - - 113.70 - - 1108 12 -- -- 1171 12 84Y - - 113.75 5069.4 628 1108 36 36 42 1045 30 85X - - 113.80 - - 1109 12 -- -- 1172 12 85Y - - 113.85 5070.0 630 1109 36 36 42 1046 30 86X - - 113.90 - - 1110 12 -- -- 1173 12 86Y - - 113.95 5070.6 632 1110 36 36 42 1047 30 87X - - 114.00 - - 1111 12 -- -- 1174 12 87Y - - 114.05 5071.2 634 1111 36 36 42 1048 30 88X - - 114.10 - - 1112 12 -- -- 1175 12 88Y - - 114.15 5071.8 636 1112 36 36 42 1049 30 89X - - 114.20 - - 1113 12 -- -- 1176 12 89Y - - 114.25 5072.4 638 1113 36 36 42 1050 30 90X - - 114.30 - - 1114 12 -- -- 1177 12 90Y - - 114.35 5073.0 640 1114 36 36 42 1051 30 91X - - 114.40 - - 1115 12 -- -- 1178 12 91Y - - 114.45 5073.6 642 1115 36 36 42 1052 30 92X - - 114.50 - - 1116 12 -- -- 1179 12 92Y - - 114.55 5074.2 644 1116 36 36 42 1053 30 93X - - 114.60 - - 1117 12 -- -- 1180 12 93Y - - 114.65 5074.8 646 1117 36 36 42 1054 30 94X - - 114.70 - - 1118 12 -- -- 1181 12 94Y - - 114.75 5075.4 648 1118 36 36 42 1055 30 95X - - 114.80 - - 1119 12 -- -- 1182 12 95Y - - 114.85 5076.0 650 1119 36 36 42 1056 30 96X - - 114.90 - - 1120 12 -- -- 1183 12 96Y - - 114.95 5076.6 652 1120 36 36 42 1057 30 97X - - 115.00 - - 1121 12 -- -- 1184 12 97Y - - 115.05 5077.2 654 1121 36 36 42 1058 30 98X - - 115.10 - - 1122 12 -- -- 1185 12 98Y - - 115.15 5077.8 656 1122 36 36 42 1059 30 99X - - 115.20 - - 1123 12 -- -- 1186 12 99Y - - 115.25 5078 4 658 1123 36 36 42 1060 30 100X - - 115.30 - - 1124 12 -- -- 1187 12 100Y - - 115.35 5079.0 660 1124 36 36 42 1061 30

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6050.32B Appendix 3, Section 1 – continued 11/17/05

FIGURE 1f. CHANNEL AND FREQUENCY PAIRING WITH DME PULSE TIME/CODES

(CONTINUED)

DME AIRBORNE DME GROUND INTERROGATE REPLY DME MLS NORMAL DME/P CHN -------------FREQUENCY---MHz---------- CHN DME IA FA DME PC NO. LOC GS VOR MLS NO. FREQ μs μs μs FREQ μs 101X - - 115.40 - - 1125 12 -- -- 1188 12 101Y - - 115.45 5079.6 662 1125 36 36 42 1062 30 102X - - 115.50 - - 1126 12 -- -- 1189 12 102Y - - 115.55 5080.2 664 1126 36 36 42 1063 30 103X - - 115.60 - - 1127 12 -- -- 1190 12 103Y - - 115.65 5080.8 666 1127 36 36 42 1064 30 104X - - 115.70 - - 1128 12 -- -- 1191 12 104Y - - 115.75 5081.4 668 1128 36 36 42 1065 30 105X - - 115.80 - - 1129 12 -- -- 1192 12 105Y - - 115.85 5082.0 670 1129 36 36 42 1066 30 106X - - 115.90 - - 1130 12 -- -- 1193 12 106Y - - 115.95 5082.6 672 1130 36 36 42 1067 30 107X - - 116.00 - - 1131 12 -- -- 1194 12 107Y - - 116.05 5083.2 674 1131 36 36 42 1068 30 108X - - 116.10 - - 1132 12 -- -- 1195 12 108Y - - 116.15 5083.8 676 1132 36 36 42 1069 30 109X - - 116.20 - - 1133 12 -- -- 1196 12 109Y - - 116.25 5084.4 678 1133 35 35 42 1070 30 110X - - 116.30 - - 1134 12 -- -- 1197 12 110Y - - 116.35 5085.0 680 1134 36 36 42 1071 30 111X - - 116.40 - - 1135 12 -- -- 1198 12 111Y - - 116.45 5085.6 682 1135 36 36 42 1072 30 112X - - 116.50 - - 1136 12 -- -- 1199 12 112Y - - 116.55 5086.2 684 1136 36 36 42 1073 30 113X - - 116.60 - - 1137 12 -- -- 1200 12 113Y - - 116.65 5086.8 686 1137 36 36 42 1074 30 114X - - 116.70 - - 1138 12 -- -- 1201 12 114Y - - 116.75 5087.4 688 1138 36 36 42 1075 30 115X - - 116.80 - - 1139 12 -- -- 1202 12 115Y - - 116.85 5088.0 690 1139 36 36 42 1076 30 116X - - 116.90 - - 1140 12 -- -- 1203 12 116Y - - 116.95 5088.6 692 1140 36 36 42 1077 30 117X - - 117.00 - - 1141 12 -- -- 1204 12 117Y - - 117.05 5089.2 694 1141 36 36 42 1078 30 118X - - 117.10 - - 1142 12 -- -- 1205 12 118Y - - 117.15 5089.8 696 1142 36 36 42 1079 30 119X - - 117.20 - - 1143 12 -- -- 1206 12 119Y - - 117.25 5090.4 698 1143 36 36 42 1080 30 120X - - 117.30 - - 1144 12 -- -- 1207 12 120Y - - 117.35 - - 1144 36 -- -- 1081 30 121X - - 117.40 - - 1145 12 -- -- 1208 12 121Y - - 117.45 - - 1145 36 -- -- 1082 30 122X - - 117.50 - - 1146 12 -- -- 1209 12 122Y - - 117.55 - - 1146 36 -- -- 1083 30 123X - - 117.60 - - 1147 12 -- -- 1210 12 123Y - - 117.65 - - 1147 36 -- -- 1084 30 124X - - 117.70 - - 1148 12 -- -- 1211 12 124Y - - 117.75 - - 1148 36 -- -- 1085 30 125X - - 117.80 - - 1149 12 -- -- 1212 12 125Y - - 117.85 - - 1149 36 -- -- 1086 30 126X - - 117.90 - - 1150 12 -- -- 1213 12 126Y - - 117.95 - - 1150 36 -- -- 1087 30

Page 6

6050.32B CHG 3 Appendix 3 Continued 06 / 11 /19 SECTION 2. VOR AND DME/TACAN FREQUENCY ENGINEERING 1. FREQUENCY ENGINEERING .

a. Frequency channelization . VOR, Distance Measuring Equipment (DME) and Tactical Air Navigation equipment (TACAN) frequencies are listed in figure 1. The frequencies 108.00/978 MHz and 108.05/1104 MHz are specifically designated for radio navigation test generators (ramp testers) and shall not be used for operational VOR and DME/TACAN facilities.

b. Use of paire d channels . The use of paired frequencies as listed in figure 1 requires that stations be collocated in accordance with one of the following: (1) Coaxial collocation . VOR and TACAN or DME antennas are located on the same vertical axis.

(2) Offset collocation for : (a) Standard VOR used in terminal areas for approach procedures, the separation of the VOR antenna and the associated DME or TACAN antenna shall not exceed 100'.

(b) Doppler VOR used in terminal areas for approach procedures, the separation of the VOR anten na and the associated DME or TACAN antenna shall not exceed 260'.

(c) Any non - terminal procedures, where the highest position - fixing accuracy of the system is required, the antenna separation limits of subparagraphs (a) and (b) apply.

(d) For all other procedures , the separation of a VOR antenna and associated DME or TACAN antenna shall not exceed 2,000'.

c. FPSV's . Figure 2a shows the three station classes : Terminal (T), Low Altitude (L), and High Altitude (H) . Figure 2b shows the two station classes : V OR Low (VL), and VOR High (VH ) .

Figure 2c shows the t wo station classes : DME Low ( D L) and DME High (DH). These volumes define the frequency protection service volumes for the VOR and/or DME/TACAN. [Note: These station class altitudes are in AGL referenc e to the site elevation.

(1) The DME Low ( D L) and DME High ( D H) are only applicable for the DME/TACAN facilities that are essential for establishing the DME - DME RNAV coverage set forth by the NextGen DME Program fPRD .

(2) The VOR Low (VL) and VOR High (VH) are only applicable for the VOR, VOR/DME, and VORTAC facilities retained by the FAA for the VOR MON Program fPRD . These two FPSV are not applicable for those facilities that are either retained only to support the DoD operational needs or any facility not op erated by the FAA.

(3) When operational needs require facilities to be used beyond their station class dimensions, the authorization for additional protected signal coverage requires an ESV that must satisfy the same signal standards/tolerances/protections and ground/flight check certification.

(a) The maximum allowable extension is 160 - NM, and the total azimuth of coverage should be less than 120 - deg from the NAVAID.

6050.32B CHG 3 Appendix 3 Continued 06 / 11 /19 (b) If more than 120 - deg is necessary, then intermediate points along the ESV’s perimeter mu st be checked for potential adjacent channel interferers.

d. VOR D/U criteria . Harmful interference to VOR facilities is avoided by geographically separating cochannel and adjacent - channel assignments. Within each FPSV, the D/U ratio shall be at least the following, on a basis of 95 percent time signal availability.

st nd Co - channel 1 Adjacent Channel 2 Adjacent Channel (±50kHz) (±100kHz) - 4 dB Interim +23 dB - 43 dB - 31 dB Final

Figure 2a. Standard Service Volumes (SSV)

6050.32B CHG 3 Appendix 3 Continued 06 / 11 /19

Figure 2 b . VOR Service Volumes

Figure 2c. DME Service Volumes

(1) A D/U ratio of - 4 dB is necessary to assure protection of 100 kHz (100 channel) navigation receivers. This - 4 dB D/U ratio is referred to as the interim criterion and shall be used to protect 100 kHz assignments.

(2) A D/U ratio of - 31 dB is for 50 kHz (200 channel) navigation receivers. This is referred to as the final criterion and shall be used for 50 kHz assignments.

(3) All the D/U ratio values include a value of +3 dB to take into account transmitter power degradation before system shutdown.

8a 6050.32B CHG 3 Appendix 3 Continued 06 / 11 /19 e. DME/TACAN D/U criteria . Harmful interference to DME/TACAN facilities is prevented in the same manner as for VOR's in subparagraph d. The +3 dB factor is included and the values are: st nd Co - channel 1 Adjace nt Channel 2 Adjacent Channel (± 1 M Hz) (± 2 M Hz) +11 dB - 39 dB - 47 dB 2. FREQUENCY ENGINEERING PROCEDURES . To ensure that the proposed VOR - DME/TACAN frequencies would provide interference - free operations within their FPSV's, the following analyses must be performed on the proposed frequencies: a. Intersite analysis is used to determine whether the proposed frequencies meet the assignment criteria as specified in subparagraphs 1d and 1e. There are two analysis methods, table and calculation.

b. In addition, d ifferences in site elevation calculations are necessary.

3. INTERSITE ANALYSIS BY THE TABLE METHOD FOR VOR . Analysis for VOR facilities may be performed on a proposed VOR frequency through the use of the following tables which show conservative/worst - case separation distances required, with respect to VOR/VOR and VOR/adjacent channel LOC: a. Figure 3 for VOR/VOR cochannel.

b. Figure 4 for VOR/VOR 1st adjacent channel (interim).

c. Figure 5 for VOR/VOR 1st adjacent channel (final).

d. Figure 6 for VOR/VOR 2nd adjacent c hannel.

e. Figure 7 for VOR/LOC Undesired 1st adjacent (interim).

f. Figure 8 for VOR/LOC Undesired 1st adjacent (final).

g. Geographical separations are not required between VOR stations and between VOR and LOC stations which differ in frequency by more than 100 kHz. Therefore, there are no tables for 3rd adjacent channel VOR separations. However, facilities that differ in frequency by 150 kHz or less should not have overlapping FPSVs.

4. INTERSITE ANALYSIS BY THE TABLE METHOD FOR DME/TACAN . DME/TACAN facility analysis may be performed on a proposed DME/TACAN frequency through the use of the following tables which show conservative/worst - case separation distances: a. Figure 9 for DME/TACAN cochannel, TACAN undesired.

b. Figure 10 for DME/TACAN 1st adjacent channel, TACAN undesired.

c. Geographical separations are not required between DME/TACAN facilities separated more than 1 channel (1 MHz). There are no tables for 2nd adjacent DME/TACAN channels.

5. DME/TACAN REQUIRED SEPARATION. In most cases, DME/TACAN facilities, s eparation is greater than for the frequency - paired VOR facility, even though the FPSVs for like categories (H, L and T) are equal.

6050.32B CHG 3 Appendix 3 Continued 06 / 11 /19 a. For example , look at the VOR and DME/TACAN tables of mileage separations in figures 3 and 9.

From figure 3, it can be seen that two cochannel L - VORs of equal power require 180 nmi separation. From figure 9, two L - DMEs or L - TACANs of equal power require 204 nmi separation. The same holds true for T - VOR and T - DME/TACAN.

b. For most power difference levels , the same is true f or H - DME/TACAN, but not all.

c. DME/TACAN spaced 63 MHz . Interference may occur between DME/TACAN spaced 63 MHz apart. Reply transmissions from Channel 17Y, for instance, could interfere with interrogation signals on Channels 80X and 80Y. This can result i n receiver desensitization. To preclude this problem, DME/TACAN ground stations shall not be assigned on frequencies which differ by 63 MHz unless they are separated by at least 15 nmi (28 km).

Channel Interr. Frequency Reply Frequency 17Y 1041 MHz 1104 MHz 80X 1104 MHz 1167 MHz 80Y 1104 MHz 1041 MHz 6. USE OF THE LARGER SEPARATION REQUIREMENT . In all cases, the larger requirement shall be used, whether it be cochannel or adjacent channel. This requires that in each VOR or DME/TACAN frequency engineering project, a determination must be made as to which has the larger mileage separation requirement, and that value used for the assignment search. This procedure is mandatory whether both of the facilities or only one of them is actually installed.

7. PERMISSI BLE USE OF TABLES . If a proposed facility meets all the requirements of all appropriate tables, the frequency request may be submitted. VOR and DME/TACAN separation are shown in figures 3 through 10.

FIGURE 3. VOR/VOR COCHANNEL SEPARATIONS (dB) +9 +6 +3 ±0 - 3 - 6 - 9 (nmi) H - VOR 370 383 390 395 398 402 406 L - VOR 138 152 167 180 195 206 212 T - VOR 090 100 110 122 134 146 161 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 4. VOR/VOR INTERIM 1ST ADJACENT CHANNEL -50 kHz- SEPARATIONS VOR DESIRED, VOR UNDESIRED FACIL -4 dB PROTECTION CLASS ----------------EIRP RATIO---------------- (dB) +9 +6 +3 ±0 -3 -6 -9 (nmi) H-VOR 233 248 259 270 284 298 305 L-VOR 70 73 76 80 85 89 93 T-VOR 40 42 44 48 51 55 57 FIGURE 5. VOR/VOR FINAL 1ST ADJACENT CHANNEL -50 kHz- SEPARATIONS VOR DESIRED, VOR UNDESIRED FACIL -31 dB PROTECTION CLASS ---------------EIRP RATIO---------------- (dB) +9 +6 +3 ±0 -3 -6 -9 (nmi) H-VOR 143 147 152 158 175 184 195 L-VOR 44 47 50 52 54 57 61 T-VOR 32 33 34 35 36 38 39 Page 11 6050.32B Appendix 3, Section 2 – continued 11/17/05 FIGURE 6. VOR/VOR 2ND ADJACENT CHANNEL -100 KHZ- SEPARATIONS VOR DESIRED, LOC UNDESIRED FACIL -31 dB PROTECTION CLASS --------------EIRP RATIO---------------- +9 +6 +3 ±0 -3 -6 -9 (nmi) H-VOR 132 135 138 140 143 146 149 L-VOR 43 44 45 46 47 48 50 T-VOR 25 25 26 26 27 28 29 FIGURE 7. VOR/LOC INTERIM 1ST ADJACENT CHANNEL -50 kHz- SEPARATIONS VOR DESIRED, LOC UNDESIRED FACIL -4 dB PROTECTION CLASS ---------------EIRP RATIO----------------- (nmi) (dB) +9 +6 +3 ±0 -3 -6 -9 H-VOR 210 225 238 250 263 275 285 L-VOR 64 67 71 73 77 80 86 T-VOR 37 40 42 44 46 50 51 Page 12 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 8. VOR/LOC FINAL 1ST ADJACENT CHANNEL -50 kHz - SEPARATIONS VOR DESIRED, LOC UNDESIRED FACIL -31 dB PROTECTION CLASS --------------EIRP RATIO---------------- +9 +6 +3 ±0 -3 -6 -9 (nmi) H-VOR 145 148 154 161 168 173 181 L-VOR 46 47 49 50 52 54 57 T-VOR 28 28 29 29 31 31 32 FIGURE 9. DME/TACAN COCHANNEL SEPARATIONS DME/TACAN DESIRED, DME/TACAN UNDESIRED +11 dB PROTECTION EIRP RATIO DISTANCE IN NM D/U DME/TACAN CLASS OF DESIRED FACILITY dB H L T +21 220 60 40 +18 260 66 45 +15 310 82 55 +12 339 102 65 +9 379 139 85 +6 385 163 98 +3 388 192 120 ±0 390 204 140 -3 392 207 161 -6 394 210 164 -9 396 212 166 -12 398 214 168 -15 401 216 172 -18 406 218 172 -21 411 220 175 Page 13 6050.32B Appendix 3, Section 2 – continued 11/17/05 FIGURE 10. DME/TACAN 1ST ADJACENT CHANNEL SEPARATIONS DME/TACAN DESIRED, TACAN UNDESIRED -39 dB PROTECTION EIRP RATIO DISTANCE IN NMI D/U DME/TACAN CLASS OF DESIRED FACILITY dB H L T +21 to ±0 145 45 30 -3 145 46 30 -6 148 48 30 -9 159 48 30 -12 163 50 30 -15 175 57 31 -18 194 63 31 -21 208 67 32 8. INTERSITE ANALYSIS BY THE CALCULATION METHOD . Intersite analysis may also be performed by calculating ESR and determining the required geographical separation for that ESR through the use of appropriate facility separation curves in figures 14-47.

a. ESR is an adjusted D/U ratio due to the differences in carrier power and antenna gain between two stations. It is defined as follows: ESR = D/U – P + P – A - + A D U D U Where: D/U = required D/U ratio - e.g., +23 dB for cochannel VOR; -4 dB for 1st adjacent channel VOR; +11 dB for cochannel DME/TACAN, etc.

P = carrier power of the desired facility in dBW.

D P = carrier power of the undesired facility in dBW.

U A = antenna gain of the desired facility in dB.

D A = antenna gain of the undesired facility in dB.

U b. If both the desired and undesired facilities have the same carrier power and antenna gain, the ESR value would be +23 dB for cochannel VOR, +11 dB for cochannel DME/TACAN.

c. VOR and DME/TACAN antennas , in most cases, are nondirectional, so the gain is the same in all horizontal directions. However, different models of antennas have somewhat different gains which have to be taken into account as shown in subparagraph a. They are: Page 14 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 11. VOR, DME, AND TACAN ANTENNA GAIN FIGURES Type Gain dBd V OR FA-none (Four loop) 2 FA-none (Doppler) 2 FA-none (Slot) 2 FA-none (Dipole Array) 4 D ME FA 10153 8 CA3167 11 FA8974 11 FA9639 11 FA9783 11 FA-none (MK3) 9 FA-none (1020 Butler) 9 FA-none (5351A Aerocom) 9 5960 (Wilcox) 8 DB-510A (ASII) 8 DBSystems Inc. (5100A) 8 TACAN FA6239/1 or /2 (RTA-2) 7 FA6339/1 or /2 (Mod RTA-2) 9 FA6339 (GRN-9 dipole) 6 FA-none (YN103/4) 9 d. Using the calculated ESR value and appropriate facility separation curves, the required geographical separation (S) can be determined. Figures 14 through 20 will be used for VOR cochannel geographical separations; figures 21 through 29 for adjacent channel VOR separations; figures 30 through 38 for adjacent channel LOC separations; figures 39 through 45 for DME/TACAN cochannel separations; and figures 46 and 47 for DME/TACAN adjacent channel separations. Figures 48-60 are reserved.

e. (S) is determined as follows : (S) = d + d D U Where: d = the distance from the desired facility to the critical point where the D intersite analysis is being made, i.e., ESV.

d = the distance from the critical point to a potential interfering facility.

U 9. SAMPLE OF COCHANNEL INTERSITE ANALYSIS BY THE CALCULATION METHOD.

Page 15 6050.32B Appendix 3, Section 2 – continued 11/17/05 FIGURE 12. VORTAC COCHANNEL INTERSITE ANALYSIS PLOT a. Calculate VOR ESR as follows (see Paragraph 8 a): ESR = +23 dB - 21.8 + 21.8 - 2 + 2 = +23 dB b. Use figure 17 (VOR facility separation curves having ESR of +23 dB) to determine (S). The distance d D is 40 nmi and the altitude (AGL) is 18,000', since the FPSV of the proposed L-VOR is 40 nmi up to 18,000'. Find the point where the d and the altitude lines intersect. (S) for that point is 180 nmi. The required separation D between the proposed VOR and the existing VOR is 180 nmi.

c. Calculate DME/TACAN ESR as follows: ESR = +11 dB - 30 + 30 - 6 + 6 = +11 dB d. Use figure 42 (DME/TACAN facility separation curves having ESR of +11 dB) to determine the required (S).

e. Determine the same 40 nmi and 18,000' intersect point . The DME/TACAN separation requirement is 204 nmi, which is the greater of the two, so this is the separation requirement.

Page 16 11/17/05 Appendix 3, Section 2 - continued 6050.32B 10. INTERSITE ANALYSIS OF ADJACENT CHANNELS . This is done in a similar manner, except a different set of curves is used (see figure 13).

FIGURE 13. VORTAC 2ND ADJACENT CHANNEL INTERSITE ANALYSIS a. Calculate VOR ESR as follows: ESR = -43 dB - 21.8 + 21.8 - 2 + 2 = -43 dB .

b. Use figure 21 (VOR/VOR facility separation curve at 1,000') to determine the required geographical separation. The distance d is 40 nmi and the ESR is -43 dB. Find the point where the d and the ESR lines D D intersect. (S) for that point is 45 nmi by interpolation. The required geographical separation between the proposed VOR and the existing VOR on the 2nd adjacent channel is thus 45 nmi. It should be pointed out that the critical point for the 2nd adjacent channel analysis is 40 nmi at 1,000' (the lower edge of the L-VOR FPSV). For cochannel analysis, the higher edge of the FPSV, i. e., 18,000' is the critical point.

c. Use figure 46 (DME/TACAN vs. DME/TACAN facility separation curve at 1,000') to determine required geographical separation. The distance at 40 nmi and 1,000' will be found to be 42 nmi by interpolation. The lower edge of the FPSV is used as in subparagraph b. The VOR separation requirement is the greater, so it will be used.

Page 17 6050.32B Appendix 3, Section 2 – continued 11/17/05 11. DIFFERENCES IN SITE ELEVATIO N. When VOR facilities differ in site elevations 1000' or more, the station separation required to protect the station with the higher site elevation must be increased as follows: H-VOR : 3 nmi for each 1,000' elevation difference L-VOR : 4 nmi " " " " " T-VOR : 7 nmi " " " " " 12. thru 13. RESERVED .

Page 18 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 14. VOR FACILITY SEPARATION CURVES FOR ESR = +14 dB FIGURE 15. VOR FACILITY SEPARATION CURVES FOR ESR = +17 dB Page 19 6050.32B Appendix 3, Section 2 – continued 11/17/05 Page 20 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 16. VOR FACILITY SEPARATION CURVES FOR ESR = +20 dB Page 21 6050.32B Appendix 3, Section 2 – continued 11/17/05 FIGURE 17. VOR FACILITY SEPARATION CURVES FOR ESR = +23 dB FIGURE 18.

Page 22 11/17/05 Appendix 3, Section 2 - continued 6050.32B VOR FACILITY SEPARATION CURVES FOR ESR = +26 dB FIGURE 19.

VOR Page 23 6050.32B Appendix 3, Section 2 – continued 11/17/05 FACILITY SEPARATION CURVES FOR ESR = +29 dB Page 24 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 20. VOR FACILITY SEPARATION CURVES FOR ESR = +32 DB FIGURE 21. ESR RATIO - VOR/VOR @ 1,000' Page 25 6050.32B Appendix 3, Section 2 – continued 11/17/05 FIGUR E 22. ESR RATIO - VOR/VOR @ 5,000' Page 26 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 23. ESR RATIO - VOR/VOR @ 10,000' Page 27 6050.32B Appendix 3, Section 2 – continued 11/17/05 Page 28 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 24. ESR RATIO - VOR/VOR @ 15,000' Page 29 6050.32B Appendix 3, Section 2 – continued 11/17/05 FIGURE 25. ESR RATIO - VOR/VOR @ 18,000' FIGURE 26. ESR RATIO - VOR/VOR @ 20,000' Page 30 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGUR E 27. ESR RATIO - VOR/VOR @ 30,000' Page 31 6050.32B Appendix 3, Section 2 – continued 11/17/05 Page 32 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 28. ESR RATIO - VOR/VOR @ 40,000' FIGUR E 29. ESR RATIO - VOR/VOR @ 50,000' Page 33 6050.32B Appendix 3, Section 2 – continued 11/17/05 FIG URE 30. ESR RATIO - VOR/LOC. VOR IS DESIRED @ 1,000' Page 34 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 31. ESR RATIO - VOR/LOC. VOR IS DESIRED @ 5,000' Page 35 6050.32B Appendix 3, Section 2 – continued 11/17/05 Page 36 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 32. ESR RATIO - VOR/LOC. VOR IS DESIRED @ 10,000' FIG URE 33. ESR RATIO - VOR/LOC. VOR IS DESIRED @ 15,000' Page 37 6050.32B Appendix 3, Section 2 – continued 11/17/05 Page 38 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 34. ESR RATIO - VOR/LOC. VOR IS DESIRED @ 18,000' Page 39 6050.32B Appendix 3, Section 2 – continued 11/17/05 FIGURE 35. ESR RATIO - VOR/LOC. VOR IS DESIRED @ 20,000' FIGU RE Page 40 11/17/05 Appendix 3, Section 2 - continued 6050.32B 36. ESR RATIO - VOR/LOC. VOR IS DESIRED @ 30,000' Page 41 6050.32B Appendix 3, Section 2 – continued 11/17/05 FIGURE 37. ESR RATIO - VOR/LOC. VOR IS DESIRED @ 40,000' Page 42 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 38. ESR RATIO - VOR/LOC. VOR IS DESIRED @ 50,000' Page 43 6050.32B Appendix 3, Section 2 – continued 11/17/05 FIGURE 39. DME/TACAN FACILITY SEPARATION CURVES FOR ESR = +2 dB FIGURE 40.

DME/TACAN FACILITY SEPARATION CURVES FOR ESR = +5 dB Page 44 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 41. DME/TACAN FACILITY SEPARATION CURVES FOR ESR = +8 dB Page 45 6050.32B Appendix 3, Section 2 – continued 11/17/05 FIGURE 42.

DME/TACAN FACILITY SEPARATION CURVES FOR ESR= +11 dB Page 46 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 43. DME/TACAN FACILITY SEPARATION CURVES FOR ESR = +14 dB Page 47 6050.32B Appendix 3, Section 2 – continued 11/17/05 Page 48 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 44. DME/TACAN FACILITY SEPARATION CURVES FOR ESR = +17 dB FIGURE 45. DME/TACAN FACILITY SEPARATION CURVES FOR ESR = +20 dB Page 49 6050.32B Appendix 3, Section 2 – continued 11/17/05 Page 50 11/17/05 Appendix 3, Section 2 - continued 6050.32B FIGURE 46. ESR RATIO - DME/TACAN TO DME/TACAN @ 1,000' Page 51 6050.32B Appendix 3, Section 2 – continued 11/17/05 FIGURE 47. ESR RATIO - DME/TACAN TO DME/TACAN @ 18,000' FIGURES 48. thru 60. RESERVED.

Page 52 (thru 60)

11/17/05 Appendix 3 - continued 6050.32B SECTION 3. ILS AND DME FREQUENCY ENGINEERING 14. FREQUENCY ENGINEERING FOR ILS AND DME .

a. ILS and DME frequencies . These frequencies and channels are listed in figure 1, section 1.

The frequencies 108.10/979 MHz and 108.15/1105 MHz are specifically designated for radio navigation test generators (ramp testers) and shall not be used for operational ILS and DME facilities.

FIGURE 61. LOC FRONT COURSE FPSVS Page 61 6050.32B Appendix 3, Section 3 – continued 11/17/05 b. Paired frequencies . Paired frequencies as listed in figure 1 require that DMEs be located on the airport near the runway for zero range indication or the transponder will be adjusted to indicate zero range.

c. FPSVs . FPSVs for the various classes of ILS/DME are shown in figures 61 through 64.

FIGURE 62. LOC BACK COURSE FPSVS Page 62 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 63. FPSV FOR ILS GS FIGURE 64. FPSVS FOR DMES ASSOCIATED WITH ILS Page 63 6050.32B Appendix 3, Section 3 – continued 11/17/05 d. ILS D/U criteria . Harmful interference to ILS and associated DME facilities is avoided by geographically separating cochannel and adjacent channel assignments. Within each FPSV, the D/U ratio shall be at least the following, on a basis of 95 percent time signal availability. All D/U ratios include the +3 dB factor per Section 2 paragraph 1b(3).

LOC Cochannel 1st Adjacent 2nd Adjacent 3rd Adjacent Channel Channel Channel (±50 kHz) (±100 kHz) (±150 kHz) +23 dB -4 dB Interim -43 dB -47 dB -31 dB Final (1) A D/U ratio of -4 dB is necessary to assure protection of 100 kHz (100 channel) navigation receivers.

This -4 dB D/U ratio is referred to as the interim criterion and shall be used whenever possible to protect 100 kHz assignments.

(2) A D/U ratio of -31 dB is for 50 kHz (200 channel) navigation receivers. This is referred to as the final criterion and shall be used for 50 kHz assignments.

GS Cochannel 1st Adjacent 2nd Adjacent 3rd Adjacent Channel Channel Channel (±150 kHz) (±300 kHz) (±450 kHz) +23 dB -17 dB -37 dB -37 dB e. DME D/U criteria . Harmful interference to DME is prevented in the same manner as for ILS.

DME Cochannel 1st Adjacent 2nd Adjacent Channel Channel (±1 MHz) (±2 MHz) +11 dB -39 dB -47 dB 15. FREQUENCY ENGINEERING PROCEDURES . To ensure that the proposed ILS and DME frequencies will provide interference-free operations within their FPSVs, the following analyses must be performed on the proposed frequencies: a. Intersite analysis is used to determine whether the proposed frequencies meet the assignment criteria specified in paragraphs 14 d. and e. There are two analysis methods — table and calculation.

Page 64 11/17/05 Appendix 3, Section 3 - continued 6050.32B b. Cosite analysis is used to avoid interference caused by interaction between the proposed ILS and DME frequencies and other frequencies, including FM/TV in the vicinity of the proposed site. The cosite analysis procedures are discussed in the appendix.

c. Other analysis shall be performed as needed, such as correction for site elevation differences.

d. Frequency compatibility with the in-place FM Broadcast environment must be assured. See Section 4 of this appendix for use of the AAM for this function.

16. INTERSITE ANALYSIS BY THE TABLE METHOD FOR ILS LOCS . Intersite analysis may be performed on a proposed ILS frequency pair through the use of the tables in figures 66 through 71 which show conservative-worst-case separation distances required with respect to ILS/ILS and ILS/adjacent channel VOR. In addition, the nature of the ILS LOC antenna pattern makes the cochannel and adjacent channel circumferences different. Those diagrams are shown in figure 65.

a. Figure 66 is for LOC/LOC cochannel.

b. Figure 67 is for LOC/LOC 1st adjacent channel (interim).

c. Figure 68 is for LOC/LOC 1st adjacent channel (final).

d. Figure 69 is for LOC/VOR undesired 1st adjacent. channel (interim).

e. Figure 70 is for LOC/VOR undesired 1st adjacent channel (final).

f. Figure 71 is for LOC/VOR undesired 2nd adjacent channel.

g. Site elevation differences require some compensation, for cochannel ILS LOCs. For Standard and Option B FPSVs, an additional 6.5 nmi must be added to r for each 1000 of altitude difference. For Options A and C t FPSVs, an additional 7 nmi must be added for r and 5.5 nmi for r , for each 1,000' See figures 65 through 71 for 1 2 r , r and r values.

t 1 2 h. There are no GS tables , since GS FPSVs are protected by the geographic area covered by the FPSV of the associated LOC. However, there can be one problem which must be checked. In a few cases, LOC 1st adjacent channels are not always paired with matched GS frequencies. See channels 18X, 18Y and 38X in figure 1, section 1. The FMO must assure that a proposed "clear" LOC does not have an associated GS frequency only 150 kHz removed from an ILS at the same airport.

i. Note that RLOS is a factor. RLOS for Standard and Option B LOC FPSV is 101 nmi. RLOS for Options A and C LOC FPSV is 123 nmi.

17. INTERSITE ANALYSIS BY THE TABLE METHOD FOR ILS-DME . ILS-DME intersite analysis may be performed on a proposed DME frequency through the use of the table in figure 72 for ILS-DME cochannel which show conservative-worst-case separation distances required and figure 73 for ILS-DME with 1st adj.

channel TACAN/DME undesired. Geographical separations are not required between DME and TACAN facilities separated more than 1 channel (1 MHz). There are no tables for 2nd adjacent DME/TACAN channels.

18. ILS-DME REQUIRED SEPARATION . ILS-DME facilities required separation is greater than for the frequency paired LOC facility. This is clearly evident from comparison of the LOC and DME/TACAN tables for paired frequencies. In addition, any DME associated with an ILS will have a much reduced FPSV, as indicated in figure 64, as compared to those otherwise operating.

Page 65 6050.32B Appendix 3, Section 3 – continued 11/17/05 19. USE OF THE LARGER SEPARATION REQUIREMENT . In all cases, the larger separation requirement shall be used, whether it be cochannel or adjacent channel. This requires that for each ILS frequency engineering project, a determination must be made as to whether the LOC or associated DME has the larger separation requirement.

20. ILS-ASSOCIATED DME ADJACENT CHANNEL UNDESIRED . In this case, the facilities will ordinarily be regular L-DME or T-DME of the VOR FPSV size. In these cases, the tables listed in paragraph 17 shall be used. As in all other cases, the larger requirement shall always be used whether cochannel or adjacent channel.

FIGURE 65. LOC SEPARATION DISTANCES DEFINED (For use with figures 66-71) Page 66 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 66. LOC/LOC COCHANNEL RADII SEPARATIONS LOC DESIRED, LOC UNDESIRED +23 dB PROTECTION EIRP RATIO D/U LOC OPTIONS A & C STD AND OPTION B dB r (nmi) r r (nmi) r 1 2 1 2 +18 74 65 47 48 +15 83 73 53 54 +12 93 82 61 61 +9 100 92 69 69 +6 106 101 78 79 +3 110 105 85 86 ±0 114 110 90 91 -3 118 115 95 96 -6 122 121 100 100 -9 # # 100 100 12 # # * * * = RLOS is 101 nmi for STD and Option B # = RLOS is 123 nmi for Options A & C FIGURE 67. LOC/LOC 1ST ADJACENT CHANNEL - 50 kHz - SEPARATIONS -- INTERIM LOC DESIRED, LOC UNDESIRED -4 dB PROTECTION EIRP RATIO OPTIONS STANDARD & D/U LOC/VOR A & C OPTION B dB r (nmi) r t t +18 31 24 +15 34 26 +12 37 28 +9 41 30 +3 52 36 ±0 57 40 -9 80 55 -12 88 62 -15 97 68 -18 106 75 Page 67 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 68. LOC/LOC 1ST ADJACENT CHANNEL - 50 kHz - SEPARATIONS -- FINAL LOC DESIRED, LOC UNDESIRED -31 dB PROTECTION EIRP RATIO OPTIONS STANDARD & D/U LOC/VOR A & C OPTION B dB r (nmi) r t t +18 17 16 +15 18 17 +12 19 18 +9 20 18 +6 22 19 +3 23 20 ±0 25 21 -3 27 22 -6 29 23 -9 31 25 -12 33 27 -15 36 29 -18 39 31 FIGURE 69. LOC/VOR 1ST ADJACENT CHANNEL - 50 kHz - SEPARATIONS -- INTERIM LOC DESIRED, VOR UNDESIRED -4dB PROTECTION EIRP RATIO OPTIONS STANDARD & D/U LOC/VOR A & C OPTION B dB r (nmi) r t t +18 35 26 +15 39 28 +12 44 31 +9 49 34 +6 55 38 +3 62 42 ±0 70 47 -3 80 53 -6 91 59 -9 103 67 -12 117 79 -15 # 94 # = Beyond RLOS Page 68 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 70. LOC/VOR 1ST ADJACENT CHANNEL - 50 kHz - SEPARATIONS -- FINAL LOC DESIRED, VOR UNDESIRED -31 dB PROTECTION EIRP RATIO OPTIONS STANDARD & D/U LOC/VOR A & C OPTION B dB r (nmi) r t t +18 23 14 +15 24 15 +12 25 16 +9 26 17 +6 27 18 +3 28 19 ±0 29 20 -3 30 22 -6 32 24 -9 35 26 -12 38 28 -15 44 31 -18 49 34 FIGURE 71. LOC/VOR 2nd ADJACENT CHANNEL - 100 kHz - SEPARATIONS LOC DESIRED, VOR UNDESIRED -43 dB PROTECTION EIRP RATIO OPTIONS STANDARD & D/U LOC/VOR A & C OPTION B dB r (nmi) r t t +18 17 11 +15 18 12 +12 19 13 +9 20 14 +6 21 15 +3 22 16 ±0 23 17 -3 24 18 -6 25 19 -9 26 20 -12 28 21 -15 30 22 -18 32 23 Page 69 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 72. ILS-DME COCHANNEL SEPARATIONS ILS-DME DESIRED, ILS-DME UNDESIRED +11 dB PROTECTION FACILITY SEPARATION CLASS DISTANCE (nmi) STD & OPTION B 101 OPTION A & C 123 FIGURE 73. ILS-DME 1ST ADJACENT CHANNEL SEPARATIONS ILS-DME DESIRED, DME/TACAN UNDESIRED -39 dB PROTECTION FACILITY SEPARATION CLASS DISTANCE (nmi) H L T STANDARD AND ALL OPTIONS 145 45 30 Note: DMEs associated with ILS are all terminal functions of equal power.

Page 70 11/17/05 Appendix 3, Section 3 - continued 6050.32B 21. INTERSITE ANALYSIS OF ILS BY CALCULATION METHOD . LOC antennas are highly directional, and introduce an additional factor into the ESR calculation process. That factor is the gain of the antenna system with respect to the desired facility.

a. ESR is an adjusted D/U ratio due to the differences in the carrier power and antenna gain between two stations. It is defined as follows: ESR= D/U - P + P - A + A + G – G D U D U U D Where: D/U = required D/U ratio +23 dB for cochannel LOC; -4 dB for 1st adjacent channel LOC; +11 dB for cochannel DME/TACAN P = carrier power of the desired facility, dBW D P = carrier power of the undesired facility, dBW U A = antenna gain of the desired facility, dBi D A = antenna gain of the undesired facility, dBi U G = relative antenna gain (dB) of desired facility, D at point of interest, with respect to the main beam antenna gain G = same for undesired facility U b. Antenna gains (main beam and relative antenna) for individual types of LOC antennas are shown in figures 74 and 111-130.

Page 71 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 74. LOC ANTENNA GAINS AND GRAPH REFERENCE NOMENCLATURE STYLE MAINBEAM FIGURE GAIN dB MK20, FA9913 LPD (14-10) 28 111 LPD (20-10) 28 FA5692, FA5693, FA5707, FA5708, FA8001, FA8002, FA8035, FA8036, FA8038, V RING 12 112 FA8621, FA8622, FA8719, FA8720, FA8843, FA8844.

FA9320 TRVLG WAVE (8 EL) 14 113 FA9325 TRVLG WAVE (14 EL) 17 114 FA9358, FA9708, FA9912 MK2, MK12. LPD 8 EL ARRAY 17 115 FA9358, FA9708, FA9912 MK2, MK12. LPD 14 EL ARRAY 20 116 FA9759, AN/GRN29, AN/GRN30 LPD 23 117 AN/GRN_27 TRVLG WAVE (14/6) 17 118 AN/GRN_27 (NARROW) PARABOLIC 17 119 AN/GRN_27 (WIDE) PARABOLIC 17 120 AN/MRN7 DIPOLE 12 121 REDLICH LPD (14-10) 26 122 MODIFIED V RING MOD V RING 12 123 1201 DIPOLE 16 124 1203 LPD 17 125 1204 DIPOLE 14 126 1261 DIPOLE 15 127 STAN37 DIPOLE 12 128 55 TWIN TEE 13 129 STANDARD 14 EL V-RING 14.6 130 NOTE: LPD = Log Periodic Dipole Page 72 11/17/05 Appendix 3, Section 3 - continued 6050.32B c. Using the calculated ESR value and appropriate facility separation curves, the required (S) can be determined.

Figures 79 through 107 will be used for LOC cochannel separations; figures 108 through 110 for adjacent channel VORs, ILS desired; figures 111 through 130 for ILS antenna radiation pattern charts; and figures 46 and 47 for DME/TACAN adjacent channel ESR curves.

d. (S) is defined as (see figure 75): (S) = d + d D U Where: d = the distance from the desired facility to a critical point where the intersite analysis is D being made.

d = the distance from that point to a potential interfering facility.

U FIGURE 75. CRITICAL POINT SEPARATION DISTANCE 22. SPECIAL CONSIDERATION FOR ILSs ON OPPOSITE ENDS OF A RUNWAY . In some congested areas, frequencies may not be available for a new ILS requirement. In that case, consideration must be given to putting the required ILS on the same frequency as the installed one on the opposite end of the runway. If this is necessary, the following restrictions apply: a. ILS identification . Each ILS, which includes any COMLOs and DMEs, if installed, must have separate and distinct identifiers.

b. Interlock requirements . Fail-safe interlock systems must be installed to prevent both ILS and any ancillary COMLO and DME from being operated simultaneously.

c. NOTAM requirement during ILS maintenance . If radiating a signal during maintenance activities is necessary, the opposite end ILS shall be NOTAMMED out of service as unusable from the Middle Marker inward. Of course, the ILS being maintained must also be NOTAMMED out of service during the maintenance period.

Page 73 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 76. LOC INTERSITE ANALYSIS BY CALCULATION 23. LOC CALCULATION EXAMPLE . Refer to figure 76. The LOC facility separation, ESR, and LOC antenna patterns curves are used in these calculations. They are found in figure 36 and figures 79 through 129.

a. The facilities are : A = Option A LOC, 25 nmi @ 6250' on 109.50 MHz, with a standard V-Ring antenna; B = T-VOR on 109.60 MHz; and New (N) is a proposed new standard LOC, 18 nmi @ 4500' on 109.50 MHz, also with a V-Ring antenna.

b. The proposed LOC has its main beam pointed directly at the T-VOR site. The FPSV of the T-VOR is 25 nmi at 12,000', and as the larger FPSV, it will be checked first. New is 2nd adjacent channel to B, so D/U = -43 dB. (Para 14 d.)

ESR = D/U - P + P - A + A + G - G (Para 21) D U D U U D (1) For B as desired and N as undesired, ESR = -43 - 22 + 13 -2 + 12 + 0 - 0 = -42 dB NOTE: With the nondirectional VOR antenna and the LOC pointed at 0° with respect to the VOR location, both G and G are zero. Refer to U D figure 30, ESR curves for ILS-VOR @ 1,000 feet; VOR is desired.

By interpolation, a 25 nmi FPSV @ -42 dB requires a separation of (S) = 27 nmi. The example shows a distance of 65 nmi, so B is protected.

Page 74 11/17/05 Appendix 3, Section 3 - continued 6050.32B (2) For N as desired and B as undesired, with "desired" roles being reversed, ESR = -43 - 13 + 22 - 12 + 2 + 0 -0 = -44 dB NOTE: Refer to figure 108. At 18 nmi and -44 dB, (S) = approximately 17 nmi.

Since the actual separation is shown as 65 nmi, that value is >> 17, so N is protected.

(3) For N as desired and A as undesired, ESR = +23 - 13 + 13 - 12 + 12 + (-7) - (-10) = +26 dB NOTE: N’s critical point is 16º off A’s main beam and 35° off its own main beam (see figure 112 for G and G ).

U D (4) Refer to figure 105 , ILS/ILS facility separation curves for ESR = +26 dB. By interpolation, 10 nmi @ 4,500' yields (S) = 55 nmi. At the critical point on N, an aircraft will be 10 nmi from N and 80 NM from A; (S) = 80 + 10 = 90 nmi. The value 90 > 55, so N will be protected.

(5) For A as Desired , and N as Undesired, ESR = +23 - 13 + 13 - 12 + 12 + (-20) – (-5) = +23 - 0 - 15 = +8 dB NOTE: A’s critical point is 133º off N’s main beam and 10º off its own main beam (fig 112).

(6) Refer to figure 99 . For 25 nmi @ 6,250', interpolation will show (S) = 67 nmi.

A’s 25 nmi FPSV plus the 45 nmi separation = 70 nmi. The value 70 > 67; A is protected.

(7) All four conditions of cochannel and adjacent channel are satisfied. Unless there is an adjacent channel GS frequency problem (see paragraph 16h), the proposed assignment could be considered safe.

(8) However, the assignment may not be made until the paired DM channel is checked .

Page 75 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 77. DME AND TACAN ANTENNA GAIN FIGURES TYPE GAIN (dB) CA3167 (Discone) 11 FA8974 ″ 11 D FA9639 ″ 11 M FA9783 ″ 11 E M3 ″ 9 596B ″ 9 1020 ″ 9 5351A (Dipole) 10 5960 8 FA 10153 8 DB-510A 8 1118 (ASII) 8 5100 A-D UNIDIRECTIONAL 12 (Fig 131) 510 A BD BIDIRECTIONAL 13 (Fig 132) T FA6239 (TRA-2) 7 A FA6339 (MOD.. TRA-2) 9 C YNI103A or YNI104A 6 A AN/GRN9 9 N GRA047 (Dipole) 6 FIGURE 78. DME INTERSITE ANALYSIS BY CALCULATION Page 76 11/17/05 Appendix 3, Section 3 - continued 6050.32B 24. DME Calculation Example. Refer to Figure 78. The DME facility separation, ESR, antenna pattern curves are used in these calculations. They are found in figures 39 through 47.

a. The facilities are: A= ILS-DME, 18 NM at 4500' on 993.0 MHz with a standard DME antenna; B= T-VOR/DME on 994.0 MHz with a standard DME antenna; N= a proposed new ILS-DME, 18 NM at 4500' with a bi-directional DME antenna.

b. The proposed directional DME antenna has its main beam pointed directly at the T-VOR/DME site. The FPSV of the T-VOR/DME is 25 NM at 12,000 feet, and has the larger FPSV. This will be checked first. N is the 1st adjacent channel to B, so D/U= − 39 dB. (Paragraph 14e.)

ESR = D/U − P + P − A + A + G − G (Paragraph 21a) D U D U U D (1) B is desired and N undesired, ESR = − 39 − 20 + 20 − 8 + 13 − 0 + 0 = − 34 dB NOTE: With the non-directional VOR/DME antenna and the bi-directional DME pointed at 0 ° with respect to the VOR/DME location, both G and G are zero. Refer to figure 46 ESR curves for U D DME/TACAN at 1,000'. The VOR/DME is desired. By interpolation, a 25 NM FPSV at − 34 dB requires a separation of (S) = 27 NM. The example shows a distance of 65 NM, B is protected.

(2) N is desired and A is undesired.

ESR = +11 − 20 +20 − 13 + 8 + 0 − ( − 6.25) = +12.25 dB NOTE: N’s critical point is 35 ° off its own main beam. Refer to figure 132.

G is − 6.5 dB off the main beam, G is 0 dB. Refer to figures 42 and 43 curves D U for DME/TACAN at ESR = 12.25 dB. By interpolation, a 10 NM FPSV at +12.25 dB requires a separation of (S) = 85 NM.

(S) = d + d (paragraph 21d) D U = 10 + 95 = 105 NM ≥ 85 NM, N is protected (3) A is desired and N is undesired ESR = +11 − 20 + 20 − 8 + 13 + ( − 9.5) − 0 = +6.5 dB Note: A is 48 ° off the backside of N’s bi-directional antenna. Refer to figure 132. G is − 9.5 dB off the U rear beam, G is 0. Refer to figures 40 and 41 curves for DME/TACAN at ESR=+6.5 dB. By D interpolation, an 18 NM FPSV requires a separation of (S) = 92 NM. The example shows a distance of 95 NM, A is protected.

Page 77 6050.32B Appendix 3, Section 3 – continued 11/17/05 25. ILS MARKERS . Markers are continuously operating low power transmitters, with antennas radiating signals in an upward direction in a fan shape. They are to indicate to the pilot flying a course that the aircraft has passed over a particular point on the ground below.

a. Markers are located at specified distances from the touchdown point on a runway, and are called "Inner", "Middle", "Outer" and "Back Course" markers (IM, MM, OM and BCM).

b. Each Marker has its own distinctive type identification. The exact identification is: (1) OM : — — — — — (continuous dashes @ 400 Hz) (2) MM : (alternating dots and dashes @ 1300 Hz) (3) IM : . . . . . . . . . . . . . (continuous dots @ 3000 Hz) (4) BCM : .. .. .. .. .. .. .. .. (alternating pairs of dots @ 3000 Hz) c. Marker frequency is 75.000 MHz . It is used for all markers, world-wide. Protection between adjacent area Markers is provided by the narrow upward antenna radiation pattern. Power and pattern are determined by Flight Inspection at the time of commissioning of the facility. Normally, the FMO is not required to do any frequency engineering. Occasionally, parallel runways close together may have the markers tuned offset in frequency to prevent RFI between the sites.

26. THRU 30. RESERVED.

FIGURE 79. LOC FACILITY SEPARATION CURVES FOR ESR = -52 dB Page 78 11/17/05 Appendix 3, Section 3 - continued 6050.32B Page 79 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 80. LOC FACILITY SEPARATION CURVES FOR ESR = -49 dB Page 80 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 81. LOC FACILITY SEPARATION CURVES FOR ESR = -46 dB Page 81 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 82. LOC FACILITY SEPARATION CURVES FOR ESR = -43 dB Page 82 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 83. LOC FACILITY SEPARATION CURVES FOR ESR = -40 dB Page 83 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 84. LOC FACILITY SEPARATION CURVES FOR ESR = -37 dB Page 84 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 85. LOC FACILITY SEPARATION CURVES FOR ESR = -34 dB Page 85 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 86. LOC FACILITY SEPARATION CURVES FOR ESR = -31 dB Page 86 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 87. LOC FACILITY SEPARATION CURVES FOR ESR = -28 dB Page 87 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 88. LOC FACILITY SEPARATION CURVES FOR ESR = -25 dB Page 88 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 89. LOC FACILITY SEPARATION CURVES FOR ESR = -22 dB Page 89 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 90. LOC FACILITY SEPARATION CURVES FOR ESR = -19 dB Page 90 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 91. LOC FACILITY SEPARATION CURVES FOR ESR = -16 dB Page 91 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 92. LOC FACILITY SEPARATION CURVES FOR ESR = -13 dB Page 92 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 93. LOC FACILITY SEPARATION CURVES FOR ESR = -10 dB Page 93 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 94. LOC FACILITY SEPARATION CURVES FOR ESR = -7 dB Page 94 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 95. LOC FACILITY SEPARATION CURVES FOR ESR = -4 dB Page 95 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 96. LOC FACILITY SEPARATION CURVES FOR ESR = -1 dB Page 96 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 97. LOC FACILITY SEPARATION CURVES FOR ESR = +2 dB Page 97 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 98. LOC FACILITY SEPARATION CURVES FOR ESR = +5 dB Page 98 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 99. LOC FACILITY SEPARATION CURVES FOR ESR = +8 dB Page 99 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 100. LOC FACILITY SEPARATION CURVES FOR ESR = +11 dB Page 100 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 101. LOC FACILITY SEPARATION CURVES FOR ESR = +14 dB Page 101 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 102. LOC FACILITY SEPARATION CURVES FOR ESR = +17 dB Page 102 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 103. LOC FACILITY SEPARATION CURVES FOR ESR = +20 dB Page 103 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 104. LOC FACILITY SEPARATION CURVES FOR ESR = +23 dB Page 104 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 105. LOC FACILITY SEPARATION CURVES FOR ESR = +26 dB Page 105 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 106. LOC FACILITY SEPARATION CURVES FOR ESR = +29 dB Page 106 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 107. LOC FACILITY SEPARATION CURVES FOR ESR = +32 dB Page 107 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 108. ESR RATIO – LOC/VOR. LOC IS DESIRED FACILITY @ 1,000' Page 108 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 109. ESR RATIO – LOC/VOR. LOC IS DESIRED FACILITY @ 4,500' Page 109 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 110. ESR RATIO – LOC/VOR. LOC IS DESIRED FACILITY @ 6,250' Page 110 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 111. LOC LPD (14-10) and (20-10) ANTENNA RADIATION PATTERNS Page 111 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 112. LOC V RING ANTENNA RADIATION PATTERN Page 112 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 113. LOC TRVLG WAVE 8 ELEMENT ANTENNA RADIATION PATTERN Page 113 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 114. LOC TRVLG WAVE 14 ELEMENT ANTENNA RADIATION PATTERN Page 114 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 115. LOC LPD 8 ELEMENT ANTENNA RADIATION PATTERN Page 115 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 116. LOC LPD 14 ELEMENT ANTENNA RADIATION PATTERN Page 116 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 117. LOC LPD GRN-29 ANTENNA RADIATION PATTERN Page 117 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 118. LOC TRVLG WAVE 14/6 ANTENNA RADIATION PATTERN Page 118 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 119. LOC PARABOLIC NARROW ANTENNA RADIATION PATTERN Page 119 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 120. LOC PARABOLIC WIDE ANTENNA RADIATION PATTERN Page 120 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 121. LOC MRN-7 DIPOLE ANTENNA RADIATION PATTERN Page 121 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 122. LOC REDLICH LPD (14-10) ANTENNA RADIATION PATTERN Page 122 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 123. LOC MODIFIED V RING ANTENNA RADIATION PATTERN Page 123 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 124. LOC 1201 DIPOLE ANTENNA RADIATION PATTERN Page 124 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 125. LOC 1203 DIPOLE ANTENNA RADIATION PATTERN Page 125 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 126. LOC 1204 DIPOLE ANTENNA RADIATION PATTERN Page 126 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 127. LOC 1261 DIPOLE ANTENNA RADIATION PATTERN Page 127 6050.32B Appendix 3, Section 3 – continued 11/17/05 FIGURE 128. LOC STAN 37 DIPOLE ANTENNA RADIATION PATTERN Page 128 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 129. LOC TWIN TEE ANTENNA RADIATION PATTERN FIGURE 130. STANDARD 14 EL V-RING Page 129 6050.32B Appendix 3, Section 3 – continued 11/17/05 Page 130 11/17/05 Appendix 3, Section 3 - continued 6050.32B FIGURE 131. DME UNIDIRECTIONAL ANTENNA RADIATION PATTERN Page 131 6050.32B Appendix 3, Section 3 - continued 11/17/05 FIGURE 132. DME BIDIRECTIONAL ANTENNA RADIATION PATTERN FIGURES 133. thru 140. RESERVED Page 132 (thru 138)

11/17/05 Appendix 3 - continued 6050.32B SECTION 4. CHECKING AN FAA PROPOSED ILS FREQUENCY WITH THE AAM 31. ILS FREQUENCY STUDY PROCEDURE .

a. The AAM must be used to determine whether a proposed FAA ILS localizer frequency will be compatible with the existing FM broadcast environment. This is a case where the FAA must accept the status quo for any and all FM stations either operating or which have been approved within the OE case process.

b. To start , select an ILS channel for the proposed installation in accordance with Section 3 of this appendix, then proceed with the steps outline in paragraph 32, below.

32. STEP-BY-STEP STUDY PROCEDURE .

a. Select "NAVAID."

b. Select "Manual Entry."

c. On the next screen; (1) Select "ILS" under "Navaid Type."

(2) Enter the coordinates of the Localizer.

(3) Enter the Localizer Identifier.

(4) Enter the Localizer Frequency.

(5) Enter the Localizer fron course (under "Rwy Hdg").

(6) Enter the Localizaer Field Elevation.

(7) Select "OK."

d. On the next screen, select "Service Volume Type," and "OK."

e. On the next screen, select "Save" the indicated file name (in which the run data will be stored for future access).

f. On the next screen, select "Navaid Data."

(1) Enter the runway length.

(2) Select the antenna type from the options presented under "Array Type."

g. Select "RF Sources" at the top of the screen, followed by : (1) Select proponent status (" P ropStatus").

Page 139 6050.32B Appendix 3, Section 4 – continued 11/17/05 (2) Enter all the proponents by selecting " A ll Non-Proponent > Proponent."

(3) For all hred highlighted FM stations (indicating incomplete record data), enter a "click" in the far left hand column (resulting in an "x" being entered).

(4) "Click" on " I nsert/Delete," and select "Delete Tagged Rows," followed by "OK."

(5) Select "File," followed by "Save, R un Simulation."

(6) Select " D isplay Results," followed by "Simulation Report" and "OK."

(7) The Run file will be displayed.

(8) To Print out the file, select " F ile" and then " P rint."

h. If the run is clear, the frequency is OK.

i. If there is a problem, plots will be available for printout and analysis. Vertical plots are not needed, since any problem at any altitude within the FPSV will rule out selecting that frequency for an ILS.

j. To obtain plots, select "Files of T ype," and "All plot files."

k. Under "File Name," select (highlight) each file (only one file can be selected at a time) with an FM station call sign associated with it, click "OK," and the file will be displayed. To print out the report, select "File" and the "Print." Click "Exit" to return to the "File Name" screen and list to select any remaining files to print out.

33. STUDY RESULTS .

a. If there are no IM points , then the selected frequency is satisfactory, as far as the in-place FM broadcast environment is concerned. It has been run against all FM stations within the search range, each being used independently as a proponent.

b. If there is any IM point , then the FM stations making up the IM combination must be studied further to include the proper antenna type, duplicate applications, etc. If there are still IM points, the frequency is not usable since the FM stations are in place and FAA cannot ask an FM station to move to accommodate a new ILS frequency.

c. Sample runs have been made for the lowest and highest assignable ILS localizer frequencies of 108.3 and 110.3 MHz, as shown in figures 142a – 142f. On 108.3 MHz, there are no IM points, but for 110.3 MHz, there is a small number of IM points, as present in the plots. Note them at the very top corner of the "arrow."

34. thru 40. RESERVED.

Page 140 11/17/05 Appendix 3, Section 4 - continued 6050.32B FIGURE 141a. AAM PRINTOUT PAGE 1 Page 141 6050.32B Appendix 3, Section 4 – continued 11/17/05 FIGURE 141b. AAM PRINTOUT PAGE 2 Page 142 11/17/05 Appendix 3, Section 4 - continued 6050.32B FIGURE 142a. AAM PRINTOUT PAGE 1 Page 143 6050.32B Appendix 3, Section 4 – continued 11/17/05 FIGURE 142b. AAM PRINTOUT PAGE 2 Page 144 11/17/05 Appendix 3, Section 4 - continued 6050.32B FIGURE 142c. AAM PRINTOUT PAGE 3 Page 145 6050.32B Appendix 3, Section 4 – continued 11/17/05 FIGURE 142d. AAM PRINTOUT PAGE 4 Page 146 11/17/05 Appendix 3, Section 4 - continued 6050.32B FIGURE 142e. AAM PRINTOUT PAGE 5 Page 147 6050.32B Appendix 3, Section 4 – continued 11/17/05 FIGURE 142f. AAM PRINTOUT PAGE 6 FIGURES 143. thru 154. RESERVED Page 148 (thru 150)

11/17/05 Appendix 3 - continued 6050.32B SECTION 5. NAVAID RECEIVER TEST FACILITIES FREQUENCY ENGINEERING 41. FREQUENCY ENGINEERING FOR VOT TEST FACILITIES . A VOT is provided to give the pilot an opportunity to check the aircraft's VOR avionics on the ground before a flight. Frequency protection for VOTs is not provided in the air.

a. The frequencies used are those found in figure 1, section 1.

b. VOT FPSVs are not specifically described , except for the Area VOT (AVOT), which is described in subparagraph d.

c. The FPSV is set by flight check inspection at the time of commissioning. The VOT check point is physically located on the field.

(1) VOT power output may not exceed 2 watts, and may be somewhat less, depending on flight inspection determination of necessary local airport coverage.

(2) VOT cochannel separation from another VOT is that distance required to assure they are beyond RLOS to each other.

d. An AVOT is a VOT whose power may exceed 2 watts, and is intended to be received in the air, or if installed at an elevated site, to cover several airports. Although it emits a special VOT signal which only tests VOR receivers, it can cause interference to other cochannel and adjacent channel operational facilities. Frequency engineering is done in the same manner as with any two VOR's and depends on the power and service volumes of the facilities involved.

42. FREQUENCY ENGINEERING FOR SECONDARY RECEIVER TEST FACILITIES . Other ground-based receiver test facilities also may radiate low power signals to test NAVAID (VOR, ILS, DME, DME/P, MLS) systems aboard an aircraft, including the antenna. They are commonly called "test generators" or "ramp testers" and are located in and operated by Fixed Base Operators or airlines facilities on an airport, and FAA Flight Inspection facilities. They are restricted as follows: a. If operated by a non-Federal entity , they must be licensed by FCC.

b. If operated by a Federal agency (including military and FAA), they must be authorized by NTIA.

c. They may operate only on the following frequencies: (1) 108.00/978, 108.05/1104 MHz for VOR/DME test, 1 W maximum.

(2) 108.10/334.70/979 MHz , for ILS/DME test, 1 W maximum.

(3) 108.15/334.55/1105 MHz , for 50 kHz ILS channel, 100 mW maximum.

(4) 5031.0/979.0 MHz , for MLS/DME/P, 1 W maximum.

d. If interference is received by aircraft in the normal testing area from nearby or strong FM Broadcast stations, a frequency other than those listed in subparagraph c above may be assigned, upon coordination with Technical Operations ATC Spectrum Engineering Services.

Page 151 6050.32B Appendix 3, Section 5 – continued 11/17/05 43. VOT FREQUENCY ENGINEERING BY THE TABLE METHOD . The tables and diagram in figures 155-157 may be used for VOT frequency engineering. If the indicated cochannel mileages are not exceeded, and the adjacent channels are compliant with paragraph 7 of this appendix, the frequency request may be filed without further study. Note that the highest power in figures 155 and 157 is 20 dBW (100 W) EIRP. Since there usually is 1.5-2.0 dB loss in cable and connectors, this encompasses VOR's of 150/200 W normal operating power closely.

Differences can be interpolated.

FIGURE 155. COCHANNEL SEPARATION OF VOT AND OPERATING VORs VOR --------VOR EIRP------------ CLASS 20 dBW 17 dBW 14 dBW SEPARATION FROM VOR'S (nmi) H 355 375 386 L 150 162 172 T 105 111 120 FIGURE 156. LOC RADII DEFINED, COCHANNEL (See Figure 157) Page 152 11/17/05 Appendix 3, Section 5 - continued 6050.32B FIGURE 157. COCHANNEL SEPARATION OF ILS AND ILS-TEST VOR --------ILS EIRP------------ CLASS 20 dBW 17 dBW 14 dBW (nmi) r r r r r r 1 2 1 2 1 2 STD & OPT B 11 32 13 35 16 38 OPTS A & C 19 43 22 49 24 54 (See Figure 156) 44. VOT FREQUENCY ENGINEERING BY THE CALCULATION METHOD . The required distance separation may also be determined by calculation. This is needed when there is a nonstandard FPSV or ESV on the cochannel operating facility. A graphical sample is shown in figure 158. A nonstandard VOR FPSV of 60 nmi radius @ 20,000' is assumed. Appropriate facility separation curves will be found in figures 159 through 161.

FIGURE 158. VOR VERSUS COCHANNEL VOT BY CALCULATION Page 153 6050.32B Appendix 3, Section 5 – continued 11/17/05 a. Calculate the EIRP of the operating VOR as follows: VOR output = 100 W = +20.0 dBW VOR antenna gain = +2 dBi VOR cable and connector losses = - 2.5 dB ______________ VOR ERP = +19.5 dBW b. Use figure 161 , the closest separation curve on the high protection side for VOR/VOT.

c. Determine the required separation by interpolation. Since this is a cochannel problem, the highest altitude of the FPSV will be used. Locating the intersection of the 20,000' altitude line and the 60 NM line, interpolation will show the required separation to be 190 NM.

45. thru 50. RESERVED Page 154 11/17/05 Appendix 3, Section 5 - continued 6050.32B FIGURE 159. VOR/VOT COCHANNEL FACILITY SEPARATION CURVES +14 dBW Page 155 6050.32B Appendix 3, Section 5 – continued 11/17/05 FIGURE 160. VOR/VOT COCHANNEL FACILITY SEPARATION CURVES +17 dBW Page 156 11/17/05 Appendix 3, Section 5 – continued 6050.32B FIGURE 161. VOR/VOT COCHANNEL FACILITY SEPARATION CURVES +20 dBW FIGURES 162. thru 164. RESERVED .

Page 157 (thru 164)

11/17/05 Appendix 3 - continued 6050.32B SECTION 6. ESV FREQUENCY ENGINEERING 51. FREQUENCY ENGINEERING FOR ESV . An ESV is a volume of airspace in addition to the normal FPSV of a NAVAID, protected from interference from other NAVAID facilities.

a. An ESV merely adds to a standard FPSV. The ESV extends the standard FPSV in a particular direction, distance, altitude, and shape. Since power availability curves are in altitude AGL, the FMO will need to make an appropriate adjustment when analyzing ESV suitability because ESVs are designated in altitude MSL.

b. An ESV can be placed on any VOR, ILS-DME or TACAN. When a DME or TACAN and VOR are paired, BOTH shall have identical ESVs for safety reasons (except in those cases where the DME ESV supports DME/DME RNAV operations). ESVs may be added to any class of NAVAID facilities, including NDBs.

c. An ESV is frequency engineered just like the parent facility using the same facility separation and ESR curves.

d. The extension of the coverage distance involves a new dimension, not covered in previous sections of this appendix. That is the power availability of the facility at the extremity of the ESV. In all standard FPSVs, the power availability of a standard NAVAID has been assured. However, extending the FPSV substantially can put the outer most critical point outside the acceptable signal level range. For example, an H-VOR has an FPSV of 130 nmi. If it were requested to protect an ESV at some azimuth out to 165 nmi, the FMO should first check signal availability before doing the whole study. Obviously, if the standard signal strength is not available at the critical point, the ESV cannot be used, regardless of the freedom from calculated interference for both cochannel and adjacent channel. The FMO should ask the proponent to adjust their requirements to meet the available signal level. If the signal level requirement is marginal, flight inspection can determine the minimum altitude.

52. MINIMUM POWER AVAILABLE REQUIREMENTS . To satisfy defined FAA national standards, the minimum powers listed in the table in figure 165 must be available at the aircraft antennas for the identified NAVAIDs. (Note: these minimum power values correspond to the powers which would be obtained from signals-in-space using isotropic (0 dB gain) receiving antennas.)

FIGURE 165. POWER AVAILABLE REQUIREMENTS FOR NAVAID RECEIVERS FACILITY MINIMUM POWER VOR -123.0 dBW @ 117.95 MHz ILS LOCALIZER -123.0 dBW @ 111.95 MHz DME & TACAN ( > 18,000’) -114.5 dBW @ 1213.0 MHz ( < 18,000’) -109.0 dBW @ 1213.0 MHz 53. AN EXAMPLE OF POWER AVAILABILITY . The typical geographic (distance vs. altitude) usable signal coverage for a VOR is shown in figure 166.

Page 165 6050.32B Appendix 3, Section 6 - continued 11/17/05 FIGURE 166. POWER AVAILABLE - VOR a. Figure 166 is a composite of VOR power available curves and is for illustrative purposes only.

b. Suppose a proposed ESV asks for 160 nmi @ 18,000' to 25,000'. (Note that this request will be for MSL altitude.) From figure 165, it will be seen that a -123 dBW level is required. Assume the site at 2,000' elevation.

c. Refer to figure 171 , the power available curves for VOR. Trace the 160 nmi line from the bottom of the graph up to the -123 dBW curve. At that intersection, follow the horizontal line to the left to find that the minimum altitude to reach the needed power level is 26,000' AGL, or 28,000' MSL. On that basis, the ESV could not be used below 28,000' MSL, at 160 nmi. The requestor would have to be informed to revise the ESV request downward in mileage or upward in ESV floor before any further study could be done.

d. Had the ESV been for 160 nmi from 28,000' - 45,000' MSL, it would have met the needs of figure 171.

54. THE INTERRELATIONSHIP OF THE VOR AND DME/TACAN ESV . If a VOR exists and there is an associated DME/TACAN, they must have identical ESVs for safety reasons (except in those cases where the DME ESV supports DME/DME RNAV operations). Refer to figure 173. It will be noted that a TACAN cannot meet a 160 nmi requirement except above 32,000' AGL. Thus any ESV which will be certified as protected must have the power availability for both collocated facilities as well as frequency protection for both before it can be approved. In the example of paragraph 53, the lowest permissible VORTAC ESV for 160 nmi would be 32,000', or some lower minimum altitude at a lesser radial distance.

55. VOR/DME/TACAN ESV DETERMINATION PROCEDURE . Once the power available has been determined to be satisfactory, the actual calculation to determine protection can begin. The same curves used for standard FPSV protection are used for ESV determination, so they will not be repeated in this section. Whenever an ESV is to be calculated, use the ESR curves associated with the facility in Section 3.

a. When an ESV is designed , it is necessary to make the determination at the critical point. That point is defined as that which is furthest from the desired facility and simultaneously closest to the undesired facility, as shown in figure 167.

Page 166 11/17/05 Appendix 3, Section 6 - continued 6050.32B FIGURE 167. CRITICAL POINT MEASUREMENT OF AN ESV b. Refer to figure 168 and figure 17 in Section 2, VOR separation curves for ESR = +23 dB. Following the 60 nmi base line of figure 17 upward to its intersection with the 20,000' line will produce the value of (S) = 235 nmi. With the 60 nmi ESV, that means any cochannel L-VOR or T-VOR must be at least 175 nmi from the desired critical point. Were the cochannel VOR an H-VOR, the ESV would be automatically protected in that direction, due to the H-VOR separation requirement of 395 nmi previously required for the two to be cochannel at standard FPSVs.

FIGURE 168. EXAMPLE OF VOR ESV BY CALCULATION c. If a DME or TACAN were collocated , the DME/TACAN separation requirement would have to be determined in the same manner. Refer to figure 42, Section 2, DME/TACAN separation curves for ESR = +11 dB. Follow the same procedure as subparagraph a. By interpolation, (S) = 235 nmi.

Page 167 6050.32B Appendix 3, Section 6 - continued 11/17/05 d. To meet the ESV protection required in figure168, it would be necessary that the nearest cochannel VOR/DME be at least 175 nmi away from the critical point. As in subparagraph a, if the nearest cochannel is an H-VOR/DME, the requirement of 395 nmi (S) would more than protect the example ESV.

e. Adjacent channel determination is made exactly the same way that a VOR/DME/TACAN FPSV is frequency engineered. Using the values of Section 2, paragraph 1e, the appropriate ESR curves are used to determine the required distance from the critical point on the ESV to the nearest adjacent channel, for both VOR and DME/TACAN.

56. ILS-DME ESV DETERMINATION PROCEDURE . An ESV on an ILS is handled the same way as the VOR in paragraph 55 using the appropriate ESR curves and the LOC antenna radiation patterns.

As indicated in section 3 , the DME function nearly always requires a greater geographical separation than its associated ILS. Therefore, the FMO should check the DME requirements first. If the DME ESV fits, the ILS ESV will nearly always fit easily.

57. ESV SPECIAL CONSIDERATIONS .

a. ESV operational radials and areas have a definite tolerance to maintain.

(1) Radials (a) VOR/DME/TACAN ±4.5°.

(b) ILS ±10°.

(c) NDB ±10°.

(2) Wedge areas (a) VOR/DME/TACAN — add 4.5° in both directions.

(b) NDB — add 10° in both directions.

(3) Holding patterns (HP) are described by an arc enclosing two radials, e.g., 306°-322°, 83 nmi, and shall enclose the HP.

b. When the FMO receives a request via the ESV Management System (ESVMS) to establish, revise or cancel and ESV, the FMO shall engineer each ESV and approve the proposed request, if appropriate, via the ESVMS. As a result of an approval, the Flight Inspection Office will conduct a flight check of the ESV. The results of this action will be communicated to Technical Operations ATC Spectrum Engineering Services (via the ESVMS) for final review and approval. Technical Operations ATC Spectrum Engineering Services will enter the approval into the ESVMS, which subsequently generates an input into the AFM national data base and a notification of the action taken back to the FMO.

c. FMO’s shall review each ESV in their service areas on a yearly basis to confirm the accuracy of the national ESV data base.

Page 168 11/17/05 Appendix 3, Section 6 - continued 6050.32B FIGURE 169. SAMPLE ESV RECORD FORMAT 58. thru 62. RESERVED Page 169 6050.32B Appendix 3, Section 6 - continued 11/17/05 FIGURE 170. POWER AVAILABLE CURVES - 100 W - VOR 0-50 NMI Page 170 11/17/05 Appendix 3, Section 6 - continued 6050.32B FIGURE 171. POWER AVAILABLE CURVES - 100 W - VOR 0-220 NMI Page 171 6050.32B Appendix 3, Section 6 - continued 11/17/05 FIGURE 172. POWER AVAILABLE CURVES - 5 KW - TACAN 0-50 NMI Page 172 11/17/05 Appendix 3, Section 6 - continued 6050.32B FIGURE 173. POWER AVAILABLE CURVES - 5 KW - TACAN 0-220 NMI Page 173 6050.32B Appendix 3, Section 6 - continued 11/17/05 FIGURE 174. POWER AVAILABLE CURVES - 100 W -CARDION DME 0-50 NMI Page 174 11/17/05 Appendix 3, Section 6 - continued 6050.32B FIGURE 175. POWER AVAILABLE CURVES - 100 W - CARDION DME 0-220 NMI Page 175 6050.32B Appendix 3, Section 6 - continued 11/17/05 FIGURE 176. POWER AVAILABLE CURVES - 100 W - MONTEK DME 0-50 NMI Page 176 11/17/05 Appendix 3, Section 6 - continued 6050.32B FIGURE 177. POWER AVAILABLE CURVES - 100W - MONTEK DME 0-220 NMI Page 177 6050.32B Appendix 3, Section 6 - continued 11/17/05 FIGURE 178. POWER AVAILABLE CURVES - 1 KW - CARDION DME 0-50 NMI Page 178 11/17/05 Appendix 3, Section 6 - continued 6050.32B FIGURE 179. POWER AVAILABLE CURVES - 1 KW - CARDION DME 0-220 NMI Page 179 6050.32B Appendix 3, Section 6 - continued 11/17/05 FIGURE 180. POWER AVAILABLE CURVES - 1 KW - MONTEK DME 0-50 NMI Page 180 11/17/05 Appendix 3, Section 6 - continued 6050.32B FIGURE 181. POWER AVAILABLE CURVES - 1 KW - MONTEK DME 0-220 NMI Page 181 6050.32B Appendix 3, Section 6 - continued 11/17/05 FIGURE 182. POWER AVAILABLE CURVES - 100W - FA10153 DME 0-50 NMI Page 182 11/17/05 Appendix 3, Section 6 - continued 6050.32B FIGURE 183. POWER AVAILABLE CURVES - 100W - FA10153 DME 0-220 NMI Page 183 6050.32B Appendix 3, Section 6 - continued 11/17/05 FIGURE 184. POWER AVAILABLE CURVES - 100W - dBS5100A DME 0-50 NMI Page 184 11/17/05 Appendix 3, Section 6 - continued 6050.32B FIGURE 185. POWER AVAILABLE CURVES - 100W - dBS5100A DME 0-220 NMI FIGURE 186 RESERVED Page 185 (thru 196)

11/17/05 Appendix 3 - continued 6050.32B SECTION 7. MLS AND DME/P FREQUENCY ENGINEERING 63. FREQUENCY ENGINEERING FOR MLS AND DME/P.

a. MLS and associated DME/P frequencies are listed in Section 1, figure 1.

b. Use of a paired channel as listed in figure 1 requires that DME/Ps be collocated with the MLS antennas, which means within 100' of the antenna.

c. FPSVs for MLS and DME/P are as shown in figures 187-190.

FIGURE 187. FPSV FOR MLS APPROACH AZIMUTH/DATA COVERAGE Page 197 6050.32B Appendix 3, Section 7 – continued 11/17/05 FIGURE 188. FPSV FOR MLS APPROACH ELEVATION COVERAGE Page 198 11/17/05 Appendix 3, Section 7 - continued 6050.32B FIGURE 189. FPSV FOR MLS BACK AZIMUTH/DATA COVERAGE Page 199 6050.32B Appendix 3, Section 7 – continued 11/17/05 FIGURE 190. FPSV FOR MLS DME/P Page 200 11/17/05 Appendix 3, Section 7 - continued 6050.32B d. The MLS approach azimuth and elevation horizontal service volumes are conical segments, 80' wide with a complex vertical service volume. Figure 191 shows the D/U values.

FIGURE 191. INTERIM MLS COCHANNEL AND ADJ. CHANNEL SEPARATION D/U VALUES COCHANNEL +26.5 dB D/U 1ST ADJ. CHANNEL -19 dB D/U 2ND ADJ. CHANNEL -23.5 dB D/U e. Harmful interference to DME/Ps associated with MLS is prevented by geographically separating cochannel and adjacent-channel assignments. Within each FPSV, the DME/P D/U ratio shall be at least the values shown in figure 192, on a basis of 95 percent availability.

FIGURE 192. DME/P COCHANNEL AND ADJACENT CHANNEL SEPARATION D/U VALUES Cochannel @ 22 nmi Same Pulse Code +9.5 dB Different Pulse Code -40.5 dB st 1 Adjacent Channel @ 22 nmi Same Pulse Code -40.5 dB Different Pulse Code -73.5 dB nd 2 Adjacent Channel @ 7 nmi Same Pulse Code -73.5 dB Different Pulse Code -73.5 dB NOTES: All D/U ratios include the +1.5 dB factor for transmitter power variation.

Cochannel and 1st adj. channel D/U values are for the protection of a 22 nmi radius.

nd 2 adjacent channel D/U values are for the protection of a 7 nmi radius.

Page 201 6050.32B Appendix 3, Section 7 – continued 11/17/05 64. FREQUENCY ENGINEERING PROCEDURES . To ensure that the proposed MLS-DME/P frequencies would provide interference-free operations within their FPSVs, the following analysis must be performed on the proposed frequencies. Intersite analysis is used to determine whether the proposed frequencies meet the assignment criteria as specified in paragraph 63 d. There are two analysis methods, table and calculation.

65. MLS INTERSITE ANALYSIS BY TABLE METHOD . Intersite analysis may be performed on a proposed MLS frequency through the use of the tables shown in figure 192, which shows conservative-worst-case separation distances. Figure 193 is for MLS/MLS cochannel and adjacent channel. Adjacent channel criteria require a minimum of 1.2 MHz separation for MLS sites at the same airport.

FIGURE 193. INTERIM MLS COCHANNEL SEPARATION DISTANCE MLS DESIRED, MLS UNDESIRED. +26.5 dB PROTECTION FACILITY CLASS SEPARATION (NMI) MLS 205 1st Adjacent Channel 32 2nd Adjacent Channel 32 Page 202 11/17/05 Appendix 3, Section 7 - continued 6050.32B 66. DME/P INTERSITE ANALYSIS BY TABLE METHOD . Intersite analysis may be performed on a proposed DME/P frequency through the use of the table shown in figure 194 which shows the conservative-worst-case separation distance.

FIGURE 194. MLS DME/P ASSIGNMENT CRITERIA DME/P VS. DME/P T-DME L-DME H-DME (nmi) nmi) (nmi) (nmi) COCHANNEL SAME CODE 205* 205 205 400 DIFFERENT CODE 50 50 170 170 1ST ADJ. CHNL SAME CODE 25 30 45 145 DIFFERENT CODE 25 30 45 145 2ND ADJ. CHNL SAME CODE 8 9 12 14 DIFFERENT CODE 8 9 12 14 *RLOS to protect MLS angle receiver at 20,000 Ν .

Pulse loading criteria: Maximum 3 DME, DME/P or TACAN sites within 50 nmi radius and within ±3 MHz.

Ground receiver protection: ±63 MHz minimum 15 nmi separation.

67. thru 70. RESERVED FIGURES 195 thru 200 RESERVED.

Page 203 (thru 210)

11/17/05 Appendix 3 - continued 6050.32B SECTION 8. LOCAL AREA AUGMENTATION SYSTEM FREQUENCY ENGINEERING 71. FREQUENCY ENGINEERING .

a. Frequencies . The Local Area Augmentation System (LAAS) is planned to operate on center frequencies from 112.050 to 117.950 MHz. However, the last upper assignable LAAS channel will be center on 117.150 MHz to protect adjacent air/ground voice communications operations. The international ICAO standard Ground Based Augmentation System (GBAS) is planned to operate on center frequencies from 108.000 to 117.950 MHz.

b. Channeling Plan . While the LAAS equipment is capable of operating with 25 kHz frequency assignments, the LAAS channel plan will only use 50 kHz frequency assignments until otherwise changed. Thus, with the present channel plan, the first adjacent channel is at 50 kHz.

(1) Time Slots. The modulation format used by the LAAS is D8PSK. This has eight separate time slots.

One transmitter will use two time slots allowing the additional time slots to be assigned on the same channel.

(2) Coverage . More than one LAAS transmitter may be required at a specific location to provide the required coverage.

(3) A/G Communications . The highest LAAS transmitter frequency to be assigned is 117.15 MHz. This limits the LAAS ground transmitter to 400 feet or greater to an A/G communications facility.

(4) FM Broadcast Immunity . The LAAS receivers conform to the ICAO Annex 10 1998 Immunity criteria.

c. FPSVs . The standard FPSV is a 23 NM cylinder up to 10,000 feet with the option for 20,000 feet coverage.

[ Note : These are referenced to site elevation (i.e., FPSV altitudes are in AGL). Adjustments must be made if MSL elevations are needed.]

d. LAAS D/U criteria . Harmful interference to LAAS facilities is avoided by geographically separating co- channel and adjacent channel VOR/LAAS/ILS assignments. Within each FPSV, the D/U ratio shall be at least the following, on a basis of 95 percent time signal availability.

FIGURE 201. LAAS/LAAS/VOR SEPARATION CRITERIA Co-Channel D/U LAAS/LAAS +26 dB LAAS/VOR +26 dB st 1 Adjacent (50 kHz) LAAS/LAAS − 46 dB LAAS/VOR − 4 dB (Interim) − 34 dB (Final) Page 211 6050.32B Appendix 3, Section 8 – continued 11/17/05 (1) D/U ratio of − 4 dB. The − 4 dB D/U ratio is referred to as the interim criterion and shall be used whenever possible to protect 100 kHz assignments (100 channel receivers).

(2) D/U ratio of − 34 dB. The − 34 dB is referred to as the final criterion and shall be used for 50 kHz assignments (200 channel receivers).

(3) All the D/U ratio values. The D/U value includes a +3 dB to take into account transmitter power degradation before system shutdown.

72. FREQUENCY ENGINEERING PROCEDURES . To ensure that the proposed LAAS frequencies would provide interference-free operations within their FPSVs, the following analyses must be performed on the proposed frequencies: a. Intersite analysis is used to determine whether the proposed frequencies meet the assignment criteria as specified in subparagraph 71d. There are two analysis methods, table and calculation. The calculation method will be used in a manner similar to that used for VOR analysis.

b. The LAAS antenna polarization is elliptical. The total ERP is 70 W, with 50 W Horizontal and 20 W Vertical.

73. INTERSITE ANALYSIS BY THE TABLE METHOD FOR LAAS . Analysis for LAAS facilities may be performed on a proposed LAAS frequency through the use of the following tables that show separation distances required, with respect to LAAS/LAAS and LAAS/VOR: a. Figure 202 for LAAS/LAAS co-channel.

b. Figure 203 for VOR/LAAS 2nd adjacent channel (interim).

c. Figure 204 for VOR/LAAS 2nd adjacent channel (final).

d. Geographical separations are not required between LAAS facilities which differ in frequency by more than 25 kHz. LAAS/VOR separations that differ in frequency by 150 kHz or less should not have overlapping FPSVs.

FIGURE 202. LAAS/LAAS CO-CHANEL SEPARATIONS 10,000 FT 159 NM 20,000 FT 206 NM Page 212 11/17/05 Appendix 3, Section 8 - continued 6050.32B st FIGURE 203. LAAS/VOR INTERIM 1 ADJACENT CHANNEL 50 kHz SEPARATIONS VOR DESIRED, LAAS UNDESIRED -4 dB PROTECTION H-VOR 250 NM L-VOR 75 NM T-VOR 40 NM st FIGURE 204. LAAS/VOR FINAL 1 ADJACENT CHANNEL 50 kHz SEPARATIONS VOR DESIRED, LAAS UNDESIRED − 34 dB PROTECTION H-VOR 187 NM L-VOR 56 NM T-VOR 35 NM Page 213 (thru 214)

11/17/05 6050.32B APPENDIX 4. TECHNICAL DATA FOR VHF/UHF LINKS FIGURE 1. TECHNICAL PARAMETERS, ATT FR8 RCL Frequency range 7125-8400 MHz RF output power Low 0 dBw, 1 W, 30 dBm High 5 dBw, 3 W, 35 dBm Emission M20F9 Power Amplifier Output 1.6 W, 32 dBm 5.0 W, 37 dBm Transmitter freq. stability ±0.0005 percent Receiver RF bandpass -3 dB @ 52 MHz -30 dB @ 86 MHz -60 dB @ 134 MHz Receiver IF bandpass -3 dB @ 44 MHz -20 dB @ 56 MHz Receiver IF frequency 70 MHz Receiver noise figure < 6 dB Receiver threshold -77 dBm, -118 dBW Image rejection > 90 dB Page 1 6050.32B Appendix 4 – continued 11/17/05 FIGURE 2. FR8 INTERFERENCE SUSCEPTIBILITY CURVES Page 2 11/17/05 Appendix 4 - continued 6050.32B FIGURE 3. TECHNICA PARAMETERS, TML L Frequency range 4.40 - 15.25 GHz 1 RF output power 50 mW (-8.2 dBW) 1 Emission 27M0F9W Spectral purity 3 dB @ 18 MHz 20 dB @ 40 MHz @ 135 MHz 0 dB Transmitter freq. stab. 0.005% ± Receiver RF bandwidth -3 dB @ 45 MHz -20 dB @ 80 MHz -60 dB @ 270 MHz Receiver IF bandwidth -3 dB @ 44 MHz -20 dB @ 60 MHz -60 dB @ 120 MHz Receiver IF frequency 70 MHz Receiver noise figure 0.5 dB 1 Receiver tangential sensitivity 17 dB -1 Image rejection 60 dB NOTE: RF and IF bandwidth may vary 20-55 MHz, depending on equipment used.

Associated antennas arabolic Reflector P (Diameter in feet) 4' -3 dB beamwidth 1.4 Ε H x 1.4 Ε V ain G 42.5 dBi -1 Max. sidelobe gain 5.0 dB Polarization H or V Page 3 6050.32B Appendix 4 – continued 11/17/05 FIGURE 4. TML INTERFERENCE SUSCEPTIBILITY CURVES Page 4 11/17/05 Appendix 4 - continued 6050.32B FIGURE 5. FAA LOW DENSITY RCL PATH DESIGN CRITERIA RADIO TYPE XMT POWER RCV THRESHOLD NOTES (dBm) (dBm) 9xx MHz UHF 12 CH +37 -87 2 UHF Hi-Pwr Option +45 DIG 1.8 GHz 1-DS1 +30 -78.5 1,2 DIG 1.8 GHz 8-DS1 +30 -75.5 1,2 DIG 1.8 GHz Hi-Pwr +35 DIG 23 GHz 8-DS-1 +16.8 -74.5 1,2 DIG 23 GHz Hi-Pwr +21.2 Notes: -6 1 - Receiver threshold at 10 BER.

2 - Receiver threshold includes 3:3 hot standby loss.

DS1 - 1.544 Mbit/sec North American rate BER = Bit Error Rate Page 5 6050.32B Appendix 4 – continued 11/17/05 FIGURE 6. MDR 6XO8 SPECIFICATIONS TRANSMIT POWER AT ANTENNA PORT er 28 MDR 6X08 Standard Pow dBm 15 dBm MDR 6X08 Low Power y R 7125-8500 Frequenc ange MHz --------------------------- -------- ------------------------------------------ ------------ -- INTERFERENCE SPECIFICATION IN dB DR-6508 M MDR-6708 Threshold 28 34 Interference, Cochannel / Threshold /Interference, Adjacent Channel -8 -8 -3 Carrier/In rference(C/I in te dB), BER = 10 17 23 -6 Carrier/Interference(C/I in dB), BER = 10 20 26 --------------------- -------- ------------------------------------------- -- ---------------------------------------------------------- MINIMUM CHANNEL SEPARATION (MHz) Transmit-to-transmit Transmitters on same antenna, same polarization 46 MHz Transmit-to-transmit Transmitter on different antennas 30 MHz Transmit-to-receive Transmitter and Receiver on same antenna, same polarization 115 MHz Transmit-to-receive Transmitter and Receiver on same antenna, different polarization 95 MHz Transmit-to-receive Transmitter and Receiver on different antennas 30 MHz ------------------------------------------------------------------------------------------------------------------------------------ RADIO TYPE CAPACITY B/W RX THRESHOLD DISPERSIVE FADE (dBm) MARGIN (dB) -3 -6 -3 -6 DS1 (MHz ) BER=10 BER=10 BER=10 BER=10 MDR-6508-2 2 1.25 -89 -87 80 78 MDR-6508-4 8 2.50 -86 -84 76 74 MDR-6508-8 8 3.75 -83 -81 67 65 MDR-6508-12 12 5.50 -81 -79 64 62 MDR-6508-16 16 7.50 -80 -78 62 60 MDR-6708-2 2 0.80 -85 -83 83 81 MDR-6708-4 4 1.25 -82 -80 79 77 MDR-6708-8 8 2.50 -79 -77 70 68 MDR-6708-12 67 65 12 3.75 -77 -75 MDR-6708-16 16 5.00 -76 -74 65 63 Page 6 11/17/05 Appendix 4 - continued 6050.32B FIGURE 7. NOMOGRAPH FOR FREE SPACE PROPAGATION LOSS Page 7 6050.32B Appendix 4 – continued 11/17/05 FIGURE 8. NOMOGRAPH FOR PARABOLIC ANTENNA GAIN Page 8 11/17/05 Appendix 4 - continued 6050.32B FIGURE 9. AVAILABLE COMPUTER ANALYSIS MODELS MSAM The Microcomputer Spectrum Analysis Models are a collection of engineering programs useful for spectrum management. These models were adapted to run on Windows computers by the NTIA. These programs have not been rigorous tested, but have been verified to be correct for many scenarios run over a number of years.

Specific programs are listed below.

a. SHADO – Calculates and plots the areas around a fixed point that are within RLOS.

b. HORIZON – Calculates the RLOS for 360º around a specified site, using an on-line digitized terrain data base.

c. PROFILE – Calculates elevation versus distance data path Profile between two specified sites using an on-line digitized data base.

d. SATAZ – The Satellite Azimuth program computes the distance and various angles from an earth station a satellite (both geostationary and nongeostationary) and from a satellite to an earth station.

e. APD – The Antenna Power Density program provides simplified procedures for estimating the near field power density of a number of common types of antennas and graphically checking the compliance of systems with different emission exposure standards or user- defined limits.

f. FDR -- Computes Frequency Dependent Rejection and optionally, frequency-distance relationships between a transmitter and a receiver.

g. ITM – Estimates radio propagation losses over irregular terrain for VHF, UHF and SHF frequencies as a function of distance and the variability of signal in time and space.

rd th h. INTMOD – Performs harmonic and intermodulation analysis of 2 and/or 3 signal of 3 , 5 th or 7 order mixing.

i. SEAM – The Single Emitter Analysis Model estimate the signal level received at a specified propagation distance in terms of the field strength or emitter power of a single emitter.

j . ANNEX1 – The program is based on the procedures outline in Annex 1 of the NTIA Manual.

It is for use as a frequency selection aid to evaluate proposals for a new station to be introduced into an existing environment of fixed and/or mobile station in the 30 – 960 MHz band.

k. LMS – Terrestrial Land Mobile Services model is a package of empirical models. It uses Okumura-Hata ITU-R-529, Cost 231 and Okumura-Hata-Davidson models.

l. BDIST -- Computes the true Bearings and great circle Distance given the coordinates of the two endpoints using the WGSD-84 ellipsoid.

Page 9 (and 10)

11/17/05 6050.32B APPENDIX 5. GLOSSARY OF ACRONYMS A AAG Aeronautical Assignment Group AAM Airspace Analysis Model AC Alternating Current AC Approach Control ACDO Air Carrier District Office ADS-B Automatic Dependant Surveillance – Broadcast AFC Area Frequency Coordinator (military) AFM Automated Frequency Management system A/G Air-to-Ground (communications) AGC Automatic Gain Control AGL Above Ground Level ALPA Air Line Pilots Association AM Amplitude Modulation (Broadcast Station) AMCP Aeronautical Mobile Communications Panel AMSL Above Mean Sea Level (altitude) ANC Air Navigation Comission AOPA Aircraft Owners and Pilots Association ARINC Aeronautical Radio, Incorporated ARP Azimuth reference pulse ARRAS Automated Remote Radio Access System ARSR Air Route Surveillance Radar ARTCC Air Route Traffic Control Center ASD Aircraft Situation Display ASDE Airport Surface Detection Equipment ASR Airport Surveillance Radar ASOS Automated Surface Observation System AS T Air Show, Temporary ATA Air Transport Association of America ATC Air Traffic Control ATCRBS Air Traffic Control Radar Beacon System ATCT Air Traffic Control Tower ATIS Automatic Terminal Information Service AVOT Area VOT AWOS Automated Weather Observing System B BC Broadcast BCM Back Course Marker BEACON Old name for ATCRBS BFTE Beacon False Target Eliminator BLM Bureau of Land Management BUEC Backup Emergency Communication (system) Page 1 6050.32B Appendix 5 – continued 11/17/05 C C3 Command and Control Communications CAP Civil Air Patrol CB Citizens Band CCCC Communications Crises Control Center CCSA Computer Controlled Spectrum Analyzer CD Clearance Delivery CFR Code of Federal Regulations CIP Capital Investment Plan CNS Communications, Navigation and Surveillance COMM Communications COMLO Compass Locator CONUS Conterminous (or Contiguous) United States (48) COTS Commercial off-the-shelf CP Construction Permit (Issued by FCC) cps Cycles per second CSV Cylindrical Service Volume CW Continuous Wave D D Desired (facility) dB Decibel dBd Decibel gain over a dipole antenna dBi Decibel gain over an isotropic antenna dBm Decibels above 1 milliwatt dBμv Decibels above 1 microvolt dBuv/m Decibels above 1 microvolt per meter DBRITE Digital Bright Radar Indicator Tower Equipment dc Direct Current DC Departure Control d Distance from the desired facility to the edge of the desired service volume D DECCO Defense Commercial Communications Office DF Direction-Finding, Direction-Finder DGPS Differential Global Positioning System DME Distance Measuring Equipment DME/N Distance Measuring Equipment - Normal DME/P Distance Measuring Equipment - Precision DOC Department of Commerce DOD Department of Defense DOD AFC Department of Defense Area Frequency Coordinator dpi Dots Per Inch DR Distance ratio DTMF Dual Tone Multiple Frequency d Distance from the undesired facility service volume edge U to the edge of the desired service volume D/U Ratio between the d and d facilities, in dB D U Page 2 11/17/05 Appendix 5 - continued 6050.32B E EA Electric Attack ECM Electronic Countermeasures (now known as EA) ECP Engineering Change Proposal ECS Emergency Communications System (also C3) EFAS En Route Flight Advisory Service EHF Extremely High Frequency EIRP Effective Radiated Power above an Isotropic antenna ELT Emergency Locator Transmitter EMC Electromagnetic Compatibility EMI Electromagnetic Interference (same as RFI) EMS Emission EPS Emergency Planning Subcommittee ER Emergency Readiness ERP Effective Radiated Power ESR Equivalent Signal Ratio ESV Expanded Service Volume ESVMS ESV Management System F FA Final Approach (MLS) FAA Federal Aviation Administration FAR Federal Air Regulations FAS Frequency Assignment Subcommittee FCC Federal Communications Commission FET Fractional Exposure Time FFT Fire Fighting Temporary (prefix) FICO Flight Inspection Central Operations FIS Flight Information Service FM Frequency Modulation FMF Facility Master File FMO Frequency Management Office(r) FOT Frequency for Optimum Transmission FPSV Frequency Protected Service Volume FRUIT False Returns Unsynchronized In Time FS Flight Standards (Division or Service) FSDO Flight Standards District Office FSFO Flight Standards Field Office FSL Free Space Loss FSS Flight Service Station FTA Facility Transmitter Authorization G GADO General Aviation District Office GAMA General Aviation Manufacturers Association GBAS Ground Based Augmentation System GC Ground Control Page 3 6050.32B Appendix 5 – continued 11/17/05 GENOT General Notice GHz GigaHertz GMF Government Master File GNSS Global Navigation Satellite System GNSSP Global Navigation Satellite System Panel GPS Global Positioning System GPS L1 GPS Civil Signal L1 GPS L5 GPS Civil Signal L5 GS Glideslope H H High Altitude (VOR/DME/TACAN) H High Power Non-directional Beacon HE High Altitude En Route (A/G) HC Helicopter Control HF High Frequency HH High power Non-directional Beacon HIWAS Hazardous Inflight Weather Advisory System Homer Nondirectional Radio Beacon HP Holding Pattern Hz Hertz I IA Initial Approach (MLS) ICAO International Civil Aviation Organization ID Identification IF Intermediate Frequency IFF Identification, Friend or Foe IFR Instrument Flight Rules ILS Instrument Landing System IM Intermodulation Product (same as Intermod) Intermod Intermodulation Product (same as IM) iOE/AAA Internet Obstruction Evaluation/Airport Airpace Analysis IRAC Interdepartment Radio Advisory Committee ISLS Improved Side Lobe Suppression ITS Institute For Telecommunications Science ITU International Telecommunication Union J JTIDS Joint Tactical Information Distribution System K kHz KiloHertz kW KiloWatt Page 4 11/17/05 Appendix 5 - continued 6050.32B L L Low Altitude (VOR/DME/TACAN) LAAS Local Area Augmentation System LAD Administrative Report LAX Los Angeles, CA ILS System Identifier LE Low Altitude En Route (A/G) LC Local Control LDRCL Low Density Radio Communications Link LF Low Frequency LIR Interrupt Report LLF Line/Frequency LLWAS Low Level Wind Shear Alert System L/MF Low and Medium Frequency bands combined LO Local Oscillator LOA Letter of Agreement LOB Line of Bearing LOC ILS Localizer LMM Compass Locator at a Middle Marker LOM Compass Locator at an Outer Marker LPTV Low Power TV LSB Lower Sideband LUF Lowest Usable Frequency (MF/HF) M MAG Military Assignment Group MALSR Medium Intensity Approach Lighting System with Runway Alignment Indicator Lights MCS Management Control System (RFIM Van) MF Medium Frequency MH Medium Power Nondirectional Beacon MHz MegaHertz MILDEP Militaary Department MLS Microwave Landing System MM Middle Marker mm/m Millimhos Per Meter mm/min Millimeters Per Minute MMS Maintenance Management System MOA Military Operating Area Mode S Specialized ATCRBS with discrete address capability MOPS Minimum Operational Performance Standards MPE Maximum Personal Exposure m/s Meters Per Second msec Millisecond MUF Maximum Usable Frequency (MF/HF) MULTICOM Special Conditional Use Frequency (FCC) mV Millivolt MWARA Major World Air Route Areas mW/cm Milliwatts Per Square Centimeter Page 5 6050.32B Appendix 5 – continued 11/17/05 N NAFEC National Airway Facilities Experimental Center (now, the FAA William J. Hughes Technical Center) NADIF NAFEC Dipole Feed NAPRS National Automated Performance Reporting System NAS National Airspace System NASE/RFI Navigational Aids Signal Evaluator/Radio Frequency Interference NAVAID Navigational Aid NBAA National Business Aircraft Association NCP NAS Change Proposal NDB Nondirectional Beacon NDI Non Development Item NEXRAD Next Generation Weather Radar NIFC National Interagency Fire Center NIST National Institute of Science and Technology nm Nautical Miles (used in computer printout copies) nmi Nautical Miles (used in text) NOCC National Operations Control Center *NRM Number of stations (NTIA Form 19-A) NRCS National Radio Communications System NRQZ National Radio Quiet Zone NSEP National Security Emergency Preparedness NSF National Science Foundation NTIA National Telecommunications and Information Administration NTIA Manual Manual of Regulation and Procedures For Federal Radio Frequency Management, published by NTIA NWS National Weather Service O OCC Operational Control Center OE Obstruction Evaluation OM Outer Marker OSHA Occupational and Safety Hazards Administration OTS Out to Service P PAR Precision Approach Radar PEL Permissible Exposure Limit PL Private Line (squelch tones) pps Pulses Per Second PROP Proponent PRR Pulse Repetition Rate (formerly PRF) PRT Pulse Repetition Time PTP Point-To-Point PTT Push-To-Talk PTTA Postal Telegraph and Telephone Authority PWR Power Page 6 11/17/05 Appendix 5 - continued 6050.32B Q None R (R) Route (used with "aeronautical Mobile") RAD Receive Antenna Dimensions (NTIA Form 19-A) *RAD Authorized Area of Operation (NTIA Form 19-A) RADHAZ Radiation Hazard RAL Receive Antenna Location (NTIA Form 19-A) RAPM Regional Associate Program Manager RBPM Radar Beacon Performance Monitor RC Resistor/Capacitor Combination RCAG Remote Control A/G facility RCAMSL Radiation Center Above Mean Sea Level RCAS Radio Coverage Analysis System RCF Remote Communications Facility RCL Radio Communications Link RCOM Recovery Communications (Previously NARACS) RCS Radio Conference Subcommittee RDARA Regional and Domestic Air Route Area RF Radio Frequency RFI Radio Frequency Interference (same as EMI) RFI Van Radio Frequency Interference Van RFIM Radio Frequency Interference Monitoring (Van or System) RLA Receive Antenna Latitude (NTIA Form 19-A) RLG Receive Antenna Longitude (NTIA Form 19-A) RLOS Radio Line Of Sight r/min Revolutions Per Minute RML Radar Microwave Link RMM Remote Maintenance Monitoring ROSHM Regional Occupational Safety and Health Manager r/s Revolutions Per Second RSC Receive State (NTIA Form19-A) RTCA RTCA, Incorporated (formerly the Radio Technical Commission for Aeronautics) RTDE Research, Test, Development and Evaluation RTR Remote Transmitter/Receiver RX or Rx Receive, Receiver S (S) Required facility geographical separation SA Spectrum Analyzer SAR Search And Rescue SARP Standards and Recommended Practices SAWS Stand Alone Weather System SCAT-I Special Category I (DGPS) SE Super High Altitude Enroute SECRA Secondary Radar (old name for ATCRBS Page 7 6050.32B Appendix 5 – continued 11/17/05 SHF Super High Frequency SIF Selective Identification Feature (modified IFF) SLC Space Loss Calculator SLS Side Lobe Suppression SMDb Spectrum Management Data Base smi Statute Miles SMO System Maintenance Office SOC System Operations Center SPS Spectrum Planning Subcommittee SSL Secure Socket Layer SSS Space Systems Subcommittee STA Special Temporary Authorization (FCC) STALO Stabilized Local Oscillator STC Station Class (NTIA Form 19-A) T T Terminal (VOR/DME/TACAN) TACAN Tactical Air Navigation TC Time Constant TDWR Terminal Doppler Weather Radar TFR Temporary Flight Restrictions TIMDS Transportable Interference Monitoring Detection System TIOA Transmitter Identification and Operation Authorization TIS Travelers Information Service Title 49 U.S.C. Codified FAA Act of 1958, as amended TLS Transponder Landing System TML Television Microwave Link T/R Transmit and Receive TRACON Terminal Radar Approach Control TSC Technical Subcommittee TSV Tailored Service Volume TV Television TWEB Transcribed Weather Broadcast TX Transmit, Transmitter TX LO Transmitter Local Oscillator U U Undesired (facility) UAT Universal Access Transceiver ufd Microfarad UHF Ultra High Frequency UNICOM Aeronautical Advisory Station (FCC) USAF United States Air Force USB Upper Sideband usec Microsecond USER ID User Identification USFS United States Forest Service Page 8 11/17/05 Appendix 5 - continued 6050.32B USN United States Navy uV/m Microvolts Per Meter V V Volt VFR Visual Flight Rules VHF Very High Frequency VIP Variable Interpulse Period VLF Very Low Frequency VOLMET Meteorological Area Weather Broadcasts VOR VHF Omnidirectional Radio Range VORTAC VOR with TACAN VOT VHF Omnidirectional Radio Range Test VPN Virtual Private Network W W Watt WAAS Wide Area Augmentation System WRC World Radiocommunication Conference WSR-88D Next Generation Weather Radar (NEXRAD) X XAD Transmit Antenna Dimensions (NTIA Form19-A) XAL Transmit Antenna Location (NTIA Form19-A) XAZ Transmit Azimuth (NTIA Form 19-A) XLA Transmit Antenna Latitude (NTIA Form19-A) XLG Transmit Antenna Longitude (NTIA Form 19-A) XSC/RSC Transmit State (NTIA Form 19-A) Y None Z None Page 9

11/17/05 6050.32B APPENDIX 6. EMISSION DESIGNATORS FACILITY TYPE/FREQUENCY BAND DESIGNATOR STATION CLASS NDB (single carrier) (190-535 kHz) 2K04A2A ALB NDB (two carrier) (190-535 kHz) 1K12XXA ALB # # # Marker Beacon [75 MHz (OM)] 800HA2A ALA Marker Beacon [75 MHz (MM)] 2K60A2A ALA Marker Beacon [75 MHz (IM/BCM)] 6K00A2A ALA # # # Localizer capture effect (108.30-111.95 MHz) 8K00A9W ALL Localizer (108.30-111.95 MHz) 2K04A2A ALL LAAS (108.025-117.950 MHz) 14K0G7DET DGP Glide Slope (328.600-335.400 MHz) 300HA1N ALG Glide Slope capture effect (328.600-335.400 MHz) 8K30A1N ALG DME (960-1215 MHz) 650KM1A AL DME/P (960-1215 MHz) 750KM1A AL TACAN (960-1215 MHz) 650KV1A AL VOR with voice (108.2000-117.9875 MHz) 20K9A9W ALO VOR without voice (108.2000-117.9875 MHz) 20K9A2A ALO MLS (5000-5250 MHz) 150KM1D ALL,ALG # # # Radar (ASDE-X) (9000-9200 MHz) 35M00P0N LR Radar (TDWR) (5600-5650 MHz) 4M00P0NAN SMD Radar (ASR-11) (2700-2900 MHz) 2M80Q3N/5M10P0N ALS Radar (ASR-9) (2700-2900 MHz) 5M00P0N ALS Radar (ASR-8) (2700-2900 MHz) 6M00P0N ALS Radar (ASR-7) (2700-2900 MHz) 8M00P0N ALS Radar (ARSR-4) (1215-1400 MHz) 5M00P0N ALS Radar (ARSR-3) (1215-1400 MHz) 6M00P0N ALS Radar (ARSR1/2) (1215-1400 MHz) 10M0P0N ALS Radar (ASDE-3) (15.7-16.2 GHz) 28M0P0N LR ATCRBS (transmit 1030 MHz - receive 1090 MHz) 6M00M1D RN ATCBI-6 (transmit 1030 MHz – receive 1090 MHz) 21M50V1D RN Mode S (transmit 1030 MHz – receive 1090 MHz) 21M50V1D RN MSSR (transmit 1030 MHz – receive 1090 MHz) 9M001D RN Multi-Lat (transmit 1030 MHz – 1090 MHz) 9M20M1D RN RPBM/CPME (transmit 1030 MHz–receive 1090 MHz) 14M00V1D ALTO # # # Voice communications using double sideband 6K00A3E FA (enroute) (118.000-136.475 and 225.000-400.000 MHz) FAC (lcl ctl, apch ctl, etc.)

FAB (ATIS, AWOS, etc.)

FLU (gnd ctl, clnc dlvy, etc.)

# # # VDL-3 (TDMA) communications 14K07WET FA (enroute) (118.000-136.475 MHz) FAC (lcl ctl, apch ctl, etc.)

FAB (ATIS, AWOS, etc.)

FLU (gnd ctl, clnc dlvy, etc.)

Page 1 6050.32B Appendix 6 – continued 11/17/05 FACILITY TYPE/FREQUENCY BAND DESIGNATOR STATION CLASS VDL-2 (FIS-only) data link communications 14K0G1DE FA (enroute) (136.425-136.475 MHz) FAC (lcl ctl, apch ctl, etc.)

# # # HF (3-30 MHz) 1K28F1B FX, FA, MA, FB, ML 3K00J3E FX, FA, MA, FB, ML 2K80J3E FX, FA, MA, FB, ML 6K00B9W FX, FA, MA, FB, ML # # # RCL (ATT FR8) (7125-8500 MHz) 20M0F9W FX RCL (Alcatel MDR6508-4) (7125-8500 MHz) 2M50D7W FX RCL (Alcatel MDR6508-8) (7125-8500 MHz) 3M75D7W FX RCL (Alcatel MDR6508-16) (7125-8500 MHz) 7M50D7W FX TML (14.40-15.35 GHz) 27M0F9W FX # # # Land Mobile (C3) (162-174 MHz) 8K10F1E FXR, FB, ML Fixed (406.100-420.000 MHz) 11K00F1D FX Page 2

11/17/05 6050.32B APPENDIX 7. FORMULAS USED IN THIS ORDER (S) Required nmi separation distance between NAVAID's or COMM's CH 11 Pg 106 APX 3 Pg 015 APX 3 Pg 073 G Gain of parabolic antenna CH 12 Pg 113 dB L Free space loss in nmi CH 12 Pg 115 fs APX 2 Pg 007 L Free space loss in feet of interferer (sub item in LEVEL out-of-band) APX 1 Pg 012 i PRR "running rabbits" interferer's frequency CH 14 Pg 182 f i f Intermod products, any set of frequencies APX 1 Pg 009 o LEVEL Maximum in-band level of power in dBm before RFI occurs APX 1 Pg 010 LEVEL Maximum out-of-band level of power in dBm before RFI occurs APX 1 Pg 012 D Slant range distance in any standard between two elevated antennas APX 1 Pg 012 a d Venn diagram RFI radii, 10, 20 or 30 dBm distances in nmi APX 1 Pg 014 RLOS Radio line of sight between two points in nmi and smi APX 2 Pg 006 ESR Equivalent signal ratio, used in connection with VOR ESV's APX 3 Pg 014 ESR Equivalent signal ratio, used in connection with ILS's and ESV's APX 3 Pg 071 Page 1 (and 2)

11/17/05 6050.32B APPENDIX 8. SOME PROCEDURES FOR RADAR ANTENNA VERTICAL PATTERN MEASUREMENT BY SOLAR MEANS 1. GENERAL . FMOs ordinarily do not perform "solar" antenna measurements (see paragraph 1601 d. of this order). When such measurements are done, the procedures described below are suggested. There are several procedures, but all have the same purpose.

a. The methods described in this chapter use the sun's electromagnetic radiant "noise" as a signal source.

Measurement is accomplished with a field strength meter or SA in either a manual or computer-controlled recording system and recorders of either pen type or floppy disc. This system also requires shutdown of the radar, since the radar antenna is connected to the measurement system. The antenna is left at its normal mechanical tilt and rotated at its normal speed, with the transmitter and receiver turned off. These "solar" procedures described below are examples of some of the available and effective procedures.

b. As the earth rotates , the sun "rises" above (or "sets" into) the horizon, and it effectively passes through the radar antenna's main beam. That relatively stable noise source is recorded at each revolution. Since the radar's rotation is very rapid with respect to the angular velocity of the sun, many antenna revolution sun passes are possible at approximately the same elevation, thus enabling the recording system to average out small differences and give a very high degree of resolution.

c. The RFIM van is equipped to make horizontal radar antenna pattern measurements. The van equipment may be used by the FMO for the vertical pattern measurements described in this appendix. Some additional equipment may be needed depending on which method of measurement is used.

d. There is considerable equipment setup and calibration required which, instead of being in the van, must be transported to the radar site, set up, taken down, then the results either manually plotted or fed into an automatic plotter back at the FMO's office.

2. TWO METHODS OF SOLAR MEASUREMENTS . Two methods of solar-based radar antenna pattern measurement are manual and automated. Each will produce quality results, but the automated method does away with any manual extrapolation, interpolation, and plotting. It produces a superior product at the expense of using a computer and considerable other equipment.

3. MANUAL MEASUREMENT . A vertical antenna pattern can be produced manually from just the NM-65T field strength meter, an attenuator, an amplifier, and a strip chart recorder. The recorded signal will be the signal received from the sun's noise radiation as the antenna sweeps past the sun's azimuth. A block diagram of the necessary equipment setup is found in figure 1, with a procedural description following.

Page 1 6050.32B Appendix 8 – continued 11/17/05 FIGURE 1. BLOCK DIAGRAM OF MANUAL MEASUREMENT a. Equipment required for a radar antenna measurement using the sun as a source is essentially the same as the setup in the RFIM van. However, the relatively weaker source (sun noise) requires extra amplification and a source of accurate time is needed.

(1) Any good high-gain amplifier with a low noise figure may be used. The AVENTEK AMG 2021 or 2022 for 1-2 GHz or the AMG 4031 for 2-4 GHz are examples.

(2) An accurate field strength meter . The Eaton NM-65T field strength meter supplied the FMOs is excellent. The later model NM-67T is also excellent for those who have it. The signal output of a quality spectrum analyzer could also be used in lieu of the field strength meter.

(3) An in-line step attenuator , with at least 30 dB total attenuation, in steps of 1 or 2 dB is required.

(4) A strip chart recorder is needed . This is a key element in the measuring package. It must have low ballistics so that it follows the detected noise signal accurately; e.g., 10 msec or less from zero to full scale. It also must be capable of quite slow paper travel to permit recording the passes in a reasonable length of paper. An HP 17401A recorder has been used satisfactorily, but this is a two channel device and requires considerable adjustment to get the crossover of the two channels to match. There are several strip chart recorders available which will do the job satisfactorily. The principal concern is that it have sufficient span to accurately record a 25-30 dB range of values and that it is capable of being set to a slow speed of around 5 millimeters per minute (mm/min).

(5) A time source accurate to a few seconds a day is required. Before using the time source, it should be coordinated with an accurate time source such as radio station WWV. If a time-tick device is available, that device can be used to put a marked tick on the recording automatically. If not, a manual mark each minute will be sufficient.

(6) An accurate determination of the sun's position is essential. The sun's position with respect to time, date, and geographical position of the radar must be accurately known, otherwise the whole measurement will be faulty. The radar's coordinates can be obtained from the IRAC authorization document, GMF files or GPS receiver. The sun's actual position minute-to-minute is determined from the Air Almanac or Nautical Almanac, published by the Naval Observatory, Washington, DC.

Page 2 11/17/05 Appendix 8 - continued 6050.32B b. Measurement procedure .

(1) Connect the system components as shown in figure 1, with the calibrating signal generator connected to the input of the in-line step attenuator.

(2) Set the in-line attenuator to 0 dB.

(3) Set and calibrate the NM-65T to the frequency of the radar.

(4) Set the NM-65T attenuator to the 0 dB position.

(5) Set the NM-65T function .

(a) The function setting is critical to the calibration procedure, thus to the overall accuracy of the measurements. Some experimentation will be necessary and will depend on many factors. Whether field intensity, direct peak, or quasi-peak function is used will depend upon the systems setup, the ballistics of the strip recorder, the radar antenna azimuth rate and the antenna beam width (±3 dB). For instance, an ARSR with a rate of 4 revolutions per minute (r/min) and a beam width of 2 ° would mean an illumination of the antenna within its beam width for 2/360 x 15 secs = 83.33 msec. That means the strip recorder has only 83 msec to reach its full swing position and come to rest before it starts down again. A 2 ° beam width of an ASR of 15 r/min would give illumination for only 2/360 x 4 secs = 22.22 msec to accomplish the same swing. Depending on the ballistics of the recorder and the time constant of the field strength meter, this could be sufficient to give an accurate reading, or could lag behind the actual value due to the "drag" resulting in an inaccurate reading.

(b) Testing of the setup must be done before the first measurement is made. Once done, the parameters will be known and set for all subsequent measurements, using the same equipment and antenna rates.

The manufacturer's instruction book should specify the slew rate of the pen. If it will make a full excursion in 20 msec or less, then both the examples in subparagraph b(5)(a) above would be operable in quasi-peak function.

However, if as is often the case with recorders which have slow paper rates, the manufacturer specifies the slew rate as 500 msec or so, another function will be required, most likely peak with 0.5 sec hold time.

(c) Peak function in the NM-65T holds the meter reading (and thus the recorder output) for 0.5 or 5 sec, switchable. This is to permit easy reading of a very short pulse, even a μsec or less. Setting the time constant to 0.5 sec would match a 500 msec slew rate of a strip recorder. The NM-65T inserts a brief "dump" voltage (a reverse voltage) at the end of the selected hold time in direct peak function to restore the charging circuit to zero quickly to be ready for the next pulse to be measured. This is satisfactory if the strip recorder is partially damped or has a slow slew rate. Damping allows the pen to return to zero safely, without "ramming" it down and possibly damaging the recorder. The 5 sec peak time constant would be acceptable for an ARSR rate of 4 r/min, but not an ASR of 15 r/min because the next illumination would come before the 5 sec "hold" time had expired.

(d) Quasi-peak in the NM-65T has a time constant of around 10 msec which is ideal for the Techni-rite 711 high-speed recorder used for antenna patterns described in chapter 13 of this order. The TR-711 would be excellent for this solar measurement, except the slowest normal speed would run out quite a bit of paper for the hour or more required for a complete sun "pass." If the TR-711 is reduced in tape speed to be usable for this function, then quasi-peak must be used, or the "dump" feature of direct peak will render the recording useless and could damage the recorder. The TR-711 has a slew rate of approximately 5 msec to full scale and no damping.

Page 3 6050.32B Appendix 8 – continued 11/17/05 (6) Calibrate the strip recorder by injecting a known signal at a level about 150 to 250 milliVolts (mV) and adjusting the recorder scan to a desired scale reading, usually about 75 percent. Experience will soon teach what level is expected to be the peak noise recorded off each type of radar antenna and frequency. The NM-65T will handle a 60 dB dynamic range of level without distortion. Should the recorded level be above scale with the in-line attenuator set at 0, insert sufficient attenuation with this device to bring the pen to an on-scale reading for the whole recording session. DO NOT reduce signal level with the NM-65T internal attenuator. Doing so would activate AGC action within the NM-65T which occurs at other than 0 dB setting and would upset recording linearity. Set the recording paper speed at an appropriate rate, nominally around 5mm/min.

(7) Insert steps of attenuation with the signal generator untouched, (maximum of 2 dB/step) so that the individual levels of attenuation are shown on the recorder paper. After step intervals of 25 to 30 dB attenuation levels have been recorded and marked on the recording strip, return the attenuator to 0 dB.

(8) Disconnect the generator and connect the radar antenna to the input of the attenuator. With the radar turned off, start the antenna rotating.

(9) Sunrise (or sunset) time will have to have been previously determined for the particular day of the measurement. The actual recording should be started 2-3 min before sunrise. If the measurement is to be made at the sunset period, start the recording in sufficient time to assure a full range of vertical azimuth desired. Also start the time ticks and assure they are marked either manually or automatically on the recording for later data resolution.

(10) Run the recording for as long as needed to show the range of vertical pattern desired. For a NADIF, for instance, this is just over an hour. Once the peak has been reached and further sun azimuthal excursion drops the sun noise passes more than 20 to 25 dB from the peak, recording may be stopped.

(11) Rerun the calibration on the recording at this time, to assure that parameters have not drifted significantly. Should they somehow have done so, it will be necessary to check all equipment and the overall system to find the cause of the apparent drift before another recording is made.

(12) Dismantle the setup and disconnect the equipment . The recording is now ready to be analyzed to permit drawing the actual radiation pattern. Refer to figure 2.

c. Data analysis . With the recorded signal in hand, it is now possible to calculate the actual vertical beam pattern. The recorder sheet already has the calibration on it, so the only analysis required is to correlate the sun's azimuth with the time ticks on the recording.

(1) Using the sun's position determined from the Naval Observatory Almanac, mark each fractional degree of sun azimuth on the recording aside the time tick marks. These should be small increments of 0.1° or so.

(2) Using the previous calibration marks , evaluate and mark each azimuth increment with a dB value.

Generally, there will be a small variation of ±1 dB or less between successive passes. If so, take a simple average of those passes nearest the marked increment.

(3) Analyzing the calibrated recording , work up a chart of vertical azimuth in degrees versus amplitude in dB. Refer to figure 3.

Page 4 11/17/05 Appendix 8 - continued 6050.32B (4) Using the data now available , plot the chart values onto a graph of expanded angular scale to produce a graphic view of the actual vertical beam antenna pattern of the radar measured. Be sure to subtract any mechanical tilt from the plot, or to specifically indicate that the plot is true vertical azimuth as installed, rather than the actual vertical radiation pattern of the antenna itself.

FIGURE 2. SAMPLE RECORDING WITH CALIBRATION, TIME AND AMPLITUDE MARKINGS Page 5 6050.32B Appendix 8 – continued 11/17/05 FIGURE 3. SAMPLE PLOT OF ANALYZED RECORDING 4. AUTOMATED MEASUREMENT . Automated systems of measurement have been developed by a few service areas to permit not only automated recording of the sun's azimuth passing through the antenna's beam, but then to produce automatically the graph of the beam resulting from the data collection. They use the equipment indicated previously in the manual method with the addition of a high-speed digital voltmeter, a real time clock, and a desktop computer. One service area used the HP 3437A voltmeter, the HP 98035A clock and the HP 9825A desktop computer. A block diagram of the setup is found in figure 4.

a. Automated mode operation is different from that of the manual mode described in paragraph 1702. The field strength meter output is fed to a digital voltmeter, then to a microcomputer which is time calibrated by a real time clock input. When the data collection is completed, the recorded information is taken back to the FMO's office and plotted by using the microcomputer and a suitable plotter. The final product is a vertical pattern plotted by the automated system.

(1) Azimuth reference is required for the system to identify the "window" to record. The purpose here is twofold. First, it greatly reduces extraneous signals from other radars from getting into the data base.

Secondly, it reduces the need for memory and permits putting the whole recording on one tape. As the block diagram shows, the radar's Azimuth Reference Pulse (ARP) is used in conjunction with the clock to open the data window only for a few degrees before and then closing it a few degrees after the antenna scans the sun area.

Page 6 11/17/05 Appendix 8 - continued 6050.32B (2) The digital voltmeter is used to assure the overall signal applied to the computer does not exceed 1.5 V, the system maximum permissible value. It also serves to integrate the ARP into the system.

(3) The microcomputer is used primarily to program the measurement system, and once done, needs only "fill-ins" to run other radar measurements. It also serves to provide magnetic tape recording of the data as it is produced. After the recording is completed, it is used to playback the data and provide program information to the plotter for the final plotting.

(4) The plotter is used purely for graphics in plotting the final graph itself. Any good plotter compatible with the program language may be used.

(5) Strip recording can be done simultaneously to allow eye viewing of real time progress of the recording session. It is valuable as a monitoring tool to assure that all peripherals are operating in their proper mode. It allows the FMO to see the increasing, peaking and decreasing levels as the sun traverses the vertical beam path. For this reason, it is shown as optional in the block diagram of figure 4.

FIGURE 4. AUTOMATED RADAR ANTENNA SOLAR MEASUREMENT BLOCK DIAGRAM b. The service area automated program upon which this description has been based is available as a 16-page, three-file program from Technical Operations ATC Spectrum Engineering Services. Other programs have been developed subsequently by other service areas and also are available through Technical Operations ATC Spectrum Engineering Services. At present, the decision as to whether the FMO should use an automated system or manual is dependent upon the FMO's choice and availability of equipment. The computer programs are not included in this manual. With the rapid growth in microcomputers, laptop computers, and engineers' knowledge of programming, any FMO who wishes to write a program is encouraged to do so. If a successful program for automated solar measurements is written, it is requested that the FMO forward it to Technical Operations ATC Spectrum Engineering Services for study and circulation to other service areas.

Page 7 6050.32B Appendix 8 – continued 11/17/05 c. A Headquarters automated system has been devised by the Technical Operations Support National Airway Systems Engineering Office. It is designed to use with ASR, ARSR and ATCRBS antennas. It utilizes low-noise amplifiers, HP 8500 series spectrum analyzers and a microcomputer with HP-Basic language. The information entitled Radar Antenna Solar Data Recording And Analysis can be procured from Technical Operations ATC Spectrum Engineering Services.

5. DOCUMENTATION . As with other engineering data described in other chapters of this manual, any and all measurements and plots will be placed in the facility file as part of the permanent engineering record of the facility. Since spectrum management records are exempt from the destruction schedule, these records will serve as a permanent record of antenna capability and performance. They also can provide important clues to any suspected improper operation of the facility.

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