1、 Recommendation ITU-R M.2008-1(02/2014)Characteristics and protection criteria for radars operating in the aeronautical radionavigation service in the frequencyband 13.25-13.40 GHzM SeriesMobile, radiodetermination, amateurand related satellite servicesii Rec. ITU-R M.2008-1 Foreword The role of the
2、 Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. Th
3、e regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy
4、for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for
5、ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting servi
6、ce (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordinat
7、ion between fixed-satellite and fixed service systems SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. El
8、ectronic Publication Geneva, 2014 ITU 2014 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R M.2008-1 1 RECOMMENDATION ITU-R M.2008-1 Characteristics and protection criteria for radars operating in the aeronauti
9、cal radionavigation service in the frequency band 13.25-13.40 GHz (2012-2014) Scope This Recommendation specifies the characteristics and protection criteria of radars operating in the aeronautical radionavigation service (ARNS) in the frequency band 13.25-13.4 GHz. The technical and operational cha
10、racteristics should be used in analysing compatibility between radars operating in the aeronautical radionavigation service and systems in other services. Keywords 13.25-13.4 GHz, radar, characteristics, protection. Abbreviations/Glossary ARNS Aeronautical radionavigation service PSD Power spectral
11、density UA Unmanned aircraft UAS Unmanned aircraft system The ITU Radiocommunication Assembly, considering a) that antenna, signal propagation, target detection, and large necessary bandwidth of radar required to achieve their functions are optimum in certain frequency bands; b) that the technical c
12、haracteristics of radars operating in the aeronautical radionavigation service (ARNS) are determined by the mission of the system and vary widely even within a frequency band, recognizing a) that the frequency band 13.25-13.4 GHz is allocated on a primary basis to aeronautical radionavigation, Earth
13、 exploration-satellite (active), and space research (active) services; b) that the Earth exploration-satellite (active) and space research (active) services operating in the frequency band 13.25-13.4 GHz shall not cause harmful interference to, or constrain the use and development of, the ARNS; c) t
14、hat representative technical and operational characteristics of systems operating in frequency bands allocated to the ARNS are required to determine the feasibility of introducing new types of systems; d) that procedures and methodologies are needed to analyse compatibility between radars operating
15、in the ARNS and systems in other services, 2 Rec. ITU-R M.2008-1 recommends 1 that the technical and operational characteristics of the radars operating in the ARNS described in the Annex should be considered representative of those operating in the frequency band 13.25-13.4 GHz and used in studies
16、of compatibility with systems in other services; 2 that Recommendation ITU-R M.1461 should be used in analysing compatibility between radars operating in the frequency band 13.25-13.4 GHz with systems in other services; 3 that the criterion of interfering signal power to radar receiver noise power l
17、evel (I/N) of 10 dB, should be used as the required protection level for the aeronautical radionavigation radars, and that this represents the aggregate protection level if multiple interferers are present. Annex Technical and operational characteristics of radars operating in the aeronautical radio
18、navigation service in the frequency band 13.25-13.40 GHz 1 Introduction ARNS system operates worldwide on a primary basis in the frequency band 13.25-13.4 GHz. This Annex presents the technical and operational characteristics of representative ARNS radars operating in this frequency band. Airborne d
19、oppler navigation systems are installed in aircraft (helicopters, as well as certain airplanes) and used for specialized applications such as continuous determination of ground speed and drift angle information of an aircraft with respect to the ground. The Radio Technical Commission for Aeronautics
20、 has developed a minimum operational performance standard for this equipment “DO-158 Airborne Doppler Radar Navigation Equipment”. In addition, radars used for collision avoidance on-board unmanned aircraft (UA) are also planned to support the integrations of unmanned aircraft system (UAS) in non-se
21、gregated airspace. 2 Technical parameters The technical parameters of radionavigation radars operating in the frequency band 13.25-13.4 GHz are presented in Table 1. All systems are operated worldwide aboard aircraft. The radars are used for aircraft on-board navigation systems for accurate navigati
22、on in all weather conditions. Rec. ITU-R M.2008-1 3 TABLE 1 Parameter Units Radar 1 Radar 2 Radar 3 Radar 4 Radar 5 Radar 6 Radar 7 Radar 8 Platform Aircraft (helicopter) Aircraft (helicopter) Aircraft (airplane) Aircraft (airplane) Aircraft (helicopter) Aircraft (airplane) Aircraft (airplane) Aircr
23、aft (helicopter) Platform maximumoperational altitude m 3 600 3 660 10 400 15 000 0-4 500 15 000 15 000 3 500 Radar type Doppler navigation radar Doppler navigation radar Doppler navigation radar Doppler navigation radar Doppler radar velocity sensorDoppler radar velocity sensorDoppler navigation ra
24、dar Doppler navigation radar The range of measured ground speed km/h 333 553 750 1 047 250 1 100 180-1 300 50-399 Frequency GHz Fixed single channel Fixed single channel Fixed single channel Fixed single channel Fixed single channel Fixed single channel 13.25 to 13.4013.295.to 13.355 Emission type C
25、ontinuous wave Intermittent continuous wave Frequency modulated-continuous wave Continuous wave Frequency modulated-continuous wave Unmodulated pulse Unmodulated continuous wave Unmodulated continuous wave Pulse width s Not applicable 1-4 Not applicable Not available Not applicable (FM) 4-7 Not appl
26、icable Not applicable Pulse rise and fall times ns Not applicable 20 Not applicable Not available Not applicable (FM) 0.2, 0.2 Not applicable Not applicable RF emission bandwidth 3 dB 20 dB40 dB kHz Not applicable2 800 20 000 100 250 350 Not applicable Not availableNot available150 1 000 5 600 95 00
27、0 Not available Not available Pulse repetition frequency pps Not applicable Not available Not applicable Not applicable Not applicable 80 000 Not applicable Not applicable Peak transmitter power W 0.85 0.132 0.18 1.0 0.050 40 20 Average 0.125.10 0.15.10 4 Rec. ITU-R M.2008-1 TABLE 1 (continued) Para
28、meter Units Radar 1 Radar 2 Radar 3 Radar 4 Radar 5 Radar 6 Radar 7 Radar 8 Receiver IF 3dBbandwidth kHz 1.4 Estimated 1.6 Estimated 55 000 2.9 Estimated 14 2 500 15 000 100 000 Sensitivity dBm 135 for 0 dB S/N 135 134 for 0 dB S/N 138 for 3 dB S/N 130 for 3 dB S/N (V = 100 m/s) 160 for 3 dB S/N (V
29、= hover) 96 for 3 dB S/N (V = 100 m/s) 110 (acquisition mode) 120 (tracking mode) 144 Receiver noise figure dB 22 (Homodyne Receiver) 22 (Dual Conversion Homodyne Receiver) 12 (Double Conversion Super Heterodyne Receiver) 22 (Homodyne Receiver) 22 (Homodyne Receiver) 7.5 Not available Not available
30、Antenna type Parabolic reflector Phased array Phased array Phased array Printed circuitarray Printed circuit array Phased array Horn-reflector Antenna placement Points towards Earth Points towards Earth Points towards Earth Points towards Earth Points towards Earth Points towards Earth Points toward
31、s Earth (Off-nadir angle 911 degrees)Points towards Earth (Off-nadir angle 18 degrees) Antenna gain dBi 27 27 26 29.5 26.5 18 20 27.8 First antenna side lobe dBi 5.5 Not available 9 14.2 at 4 degrees 10 10 7 7.2 Horizontal beamwidth degrees 7 3.3 9 4.7 4.0 20 Not available Not available Vertical bea
32、mwidth degrees 4.5 5 3 2.5 3.4 4.2 Not available Not available Polarization Linear Not available Not available Linear Linear Linear Not available Not available Number of beams 4 4 4 4 4 2 3 or 4 3 Rec. ITU-R M.2008-1 5 TABLE 1 (end) Parameter Units Radar 1 Radar 2 Radar 3 Radar 4 Radar 5 Radar 6 Rad
33、ar 7 Radar 8 Antenna beam configuration Employs Janus system. Approximate four corners of a pyramid witheach 18 degrees off-nadir Not available Employs Janus system. Approximate four corners of a pyramid with each 16 degrees off-nadir and 10.5 degrees laterally Employs Janus system Employs Janus sys
34、tem. Approximate four corners of a pyramid with each 20 degrees off-nadir Two beams Not available Not available Antenna scan Scan is one beam at a time for each corner of the pyramidScan is one beam at a time for each corner of the pyramid Scan is one beam at a time for each corner of the pyramid No
35、t available Scan is one beam at a time for each corner of the pyramid Not available Not available Not available Protection criteria dB 10 10 10 10 10 10 10 10 Notes to the Table: NOTE 1 The service ceiling of helicopters is generally lower than 7 000 m above mean sea level (MSL), while the service c
36、eiling of fixed-wing maritime patrol aircraft is approximately 15 000 m MSL. NOTE 2 The sensitivity calculation (assuming a minimum 3 dB S/N requirement for tracking) for a Doppler system must account for the bandwidth of the receivers tracker. Sensitivity calculated with respect to the wide-open re
37、ceiver bandwidth will yield a relatively low figure compared with the sensitivity based on the trackers dynamic bandwidth. In a current-generation tracker, this bandwidth is comparable to the bandwidth of the back-scattered radar signals spectrum, which itself varies with the velocity of the aircraf
38、t. NOTE 3 The actual instantaneous pointing direction of individual antenna beams depends on the installation attitude of the airborne Doppler radar with respect to the aircraft reference axes (it is not always level), as well as the pitch and roll state of the aircraft. Helicopters flying search pa
39、tterns or making abrupt acceleration/deceleration manoeuvres will often have roll and pitch values in excess of 30 degrees for short periods of time. The attitude excursions for high-performance military helicopters are even higher. NOTE 4 For systems where no noise figure is available, assume a val
40、ue of 12 dB for systems employing IF receivers and 22 dB for Homodyne (zero IF) receivers. Reference Fried, W. R.: Principles and Performance Analysis of Doppler Navigation Systems, IRE Trans., Vol. ANE-4, pp.176-196, December 1957. 6 Rec. ITU-R M.2008-1 3 Characteristics of aeronautical radionaviga
41、tion systems Aircraft radionavigation radars in the frequency band 13.25-13.4 GHz operate continuously during flight to determine speed and heading. This encompasses an altitude range from just off the ground to approximately 4 500 m for helicopter and 15 000 m for aircraft. Flight times can vary fo
42、r many hours, and typically the majority of the flight time is spent en route, but also some linger time at either the departure or destination points is expected. The Janus doppler radar navigation system uses four antenna beams as shown in Fig. 1; two fore and two aft, on the two sides of the grou
43、nd track, to compute the aircraft velocity vector referenced to the terrain by measuring the doppler shift of the ground echo from the beams. The beams may transmit in pairs or sequentially, depending on the system design. Figure 2 shows the antenna beam pattern on the iso-doppler lines. Antenna sta
44、bilizing hardware or software keeps the antenna pointing towards the ground. When the IF bandwidth, IF_BWIFBWin Hertz, is not available, the following approximation may be used: saBfvBWIFwc/)sin(*2_ = where: IF_BW: IF bandwidth (Hz) v: Aircraft velocity (m/s) fc: Centre frequency (Hz) Bw: Antenna be
45、am width 3 dB in radians a: Beam depression angle s: Speed of light (m/s). For Janus radar systems an additional factor of 1.414 is included. Reference Fried, W.R.: Principles and Performance Analysis of Doppler Navigation Systems, IRE Trans., Vol. ANE-4, pp. 176-196, December 1957. FIGURE 1 Example
46、 antenna beam pattern configuration from the aircraft M.2008-01Angleof beamdepressionStarboardfrontbeamAircraftPortfrontbeamStarboardbackbeamPortbackbeamRec. ITU-R M.2008-1 7 FIGURE 2 Example antenna beam pattern on the iso-doppler lines M.2008-0221344 Characteristics of aeronautical radionavigation
47、 sense and avoid radar The safe flight operation of UA necessitates advanced techniques to detect and track nearby aircraft, terrain, and obstacles to navigation. UA must avoid these objects in the same manner as manned aircraft. The remote pilot will need to be aware of the environment within which
48、 the aircraft is operating, be able to identify the potential threats to the continued safe operation of the aircraft, and take the appropriate action. The sense and avoid radar is an unmanned aircraft collision avoidance system whose primary function is to provide the capability to detect, track an
49、d report air traffic information to the user in order to maintain adequate separation from intruders. The system utilizes a “Pilot-in-the-Loop” approach in which the ground-based UA pilot will have final authority regarding UAS avoidance manoeuvers. The technical parameters are provided in Table 2. TABLE 2 Technical parameters of sense and avoid radar Parameter Units Radar 1 Radar 2 Platform Aircraft Aircraft Platform height km Up to 20 Up to 15.5 Radar type Air-to-air traffic collision avoidance system (doppler radar navigation aids) Air-to-air
