1、 Recommendation ITU-R M.1796-2(02/2014)Characteristics of and protection criteria for terrestrial radars operating in the radiodetermination service in the frequency band 8 500-10 680 MHzM SeriesMobile, radiodetermination, amateurand related satellite servicesii Rec. ITU-R M.1796-2 Foreword The role
2、 of the 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 adop
3、ted. The 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
4、Policy 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 Poli
5、cy for 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 Broadcastin
6、g service (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 co
7、ordination 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-
8、R 1. Electronic 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.1796-2 1 RECOMMENDATION ITU-R M.1796-2 Characteristics of and protection criteria for terrestrial radars oper
9、ating in the radiodetermination service in the frequency band 8 500-10 680 MHz*(2007-2012-2014) Scope This Recommendation provides the technical and operational characteristics and protection criteria for radiodetermination systems operating in the frequency band 8 500-10 680 MHz. It was developed w
10、ith the intention to support sharing studies in conjunction with Recommendation ITU-R M.1461 addressing analysis procedures for determining compatibility between radars operating in the radiodetermination service and other services. Keywords Radar, Protection criteria, Search radar, Interference, ra
11、diodetermination Abbreviations/Glossary CFAR Constant-false-alarm-rate IMO International Maritime Organization pps Pulses per second SART Search and rescue transponder The ITU Radiocommunication Assembly, considering a) that antenna, signal propagation, target detection, and large necessary bandwidt
12、h characteristics of radars to achieve their functions are optimum in certain frequency bands; b) that the technical characteristics of radiodetermination radars are determined by the mission of the system and vary widely even within a frequency band; c) that ITU-R is considering the potential for t
13、he introduction of new types of systems or services in frequency bands between 420 MHz and 34 GHz used by radars in the radiodetermination service; d) that representative technical and operational characteristics of radars operating in the radiodetermination service are required to determine, if nec
14、essary, the feasibility of introducing new types of systems into frequency bands allocated to the radiodetermination service, noting a) that technical and operational characteristics of maritime radar beacons operating in the frequency band 9 300-9 500 MHz are to be found in Recommendation ITU-R M.8
15、24; *Characteristics of meteorological ground-based radars operating in this frequency band are contained in Recommendation ITU-R M.1849. 2 Rec. ITU-R M.1796-2 b) that technical parameters of radar target enhancers operating in the frequency band 9 300-9 500 MHz are to be found in Recommendation ITU
16、-R M.1176; c) that technical and operational characteristics of search and rescue radar transponders (SART) operating in the frequency band 9 200-9 500 MHz are to be found in Recommendation ITU-R M.628, recognizing a) that the required protection criteria depend upon the specific types of interferin
17、g signals; b) that the application of protection criteria may require consideration for the inclusion of the statistical nature of the application of those criteria and other elements of the methodology for performing compatibility studies (e.g. propagation loss). Further development of these statis
18、tical considerations, together with the required probability of detection for various maritime operational scenarios may be incorporated into future revisions of this Recommendation, as appropriate, recommends 1 that the technical and operational characteristics of the radiodetermination radars desc
19、ribed in Annex 1 should be considered representative of those operating in the frequency band 8 500-10 680 MHz; 2 that this Recommendation, in conjunction with Recommendation ITU-R M.1461, should be used in analysing compatibility between radiodetermination radars and systems in other services; 3 th
20、at the criterion of interfering signal power to radar receiver noise power level, an I/N ratio of 6 dB, should be used as the required protection level for radiodetermination radars in the frequency band 8 500-10 680 MHz, even if multiple interferers are present (see Note 1); 4 that the results of i
21、nterference susceptibility trials performed on shipborne radionavigation radars operating in the frequency band 9 200-9 500 MHz, which are contained in Annex 3, should be used in assessing interference into shipborne radionavigation radars, noting that the results are for non-fluctuating targets and
22、 that radar cross-section (RCS) fluctuations should be taken into account. NOTE 1 Further information is provided in Annex 2. Annex 1 Technical and operational characteristics of radars in the radiodetermination service in the frequency band 8 500-10 680 MHz 1 Introduction The characteristics of rad
23、iodetermination radars operating worldwide in the frequency band 8 500-10 680 MHz are presented in Tables 1, 2, 3 and 4, and described further in the following paragraphs. Rec. ITU-R M.1796-2 3 2 Technical characteristics The frequency band 8 500-10 680 MHz is used by many different types of radars
24、on land-based, transportable, shipboard, and airborne platforms. Radiodetermination functions performed in the frequency band include airborne and surface search, ground-mapping, terrain-following, navigation (both aeronautical and maritime), target-identification, and meteorological (both airborne
25、and ground-based). Other major differences among the radars include transmit duty cycles, emission bandwidths, presence and types of intra-pulse modulation, frequency-agile capabilities of some, transmitter peak and average powers, and types of transmitter RF power devices. These characteristics, in
26、dividually and in combination, all have major bearing on the compatibility of the radars with other systems in their environment, while other characteristics affect that compatibility to lesser degrees. Radar operating frequencies can be assumed to be uniformly spread throughout each radars tuning f
27、requency band. Tables 1, 2, 3 and 4 contain technical characteristics of representative radiolocation and radionavigation radars deployed in the frequency band 8 500-10 680 MHz with the exception of ground based meteorological radars, which are contained in Recommendation ITU-R M.1849. The major rad
28、iolocation radars operating in this frequency band are primarily used for detection of airborne objects. They are required to measure target altitude as well as range and bearing. Some of the airborne targets are small and some are at ranges as great as 300 nautical miles ( 556 km), so these radiolo
29、cation radars must have great sensitivity and must provide a high degree of suppression to all forms of clutter return, including that from sea, land, and precipitation. In some cases, the radar emissions in this frequency band are required to trigger radar beacons. Largely because of these mission
30、requirements, the radars using this frequency band tend to possess the following general characteristics: they tend to have low to medium (from 1 W to 250 000 W) transmitter peak and average power, with notable exceptions; they typically use master-oscillator power-amplifier transmitters rather than
31、 power oscillators. They are usually tunable, and some of them are frequency-agile. Some of them use linear or non-linear FM (chirp) or phase-coded intra-pulse modulation; some of them have antenna main beams that are steerable in one or both angular dimensions using electronic beam steering; they t
32、ypically employ versatile receiving and processing capabilities, such as auxiliary sidelobe-blanking receive antennas, processing of coherent-carrier pulse trains to suppress clutter return by means of moving-target-indication, constant-false-alarm-rate (CFAR) techniques, and, in some cases, adaptiv
33、e selection of operating frequencies based on sensing of interference on various frequencies; individual radars often have numerous different pulse widths and pulse repetition frequencies; some chirp radars have a choice of chirp bandwidths; and some frequency-agile radars have a variety of agile- o
34、r fixed-frequency modes. This flexibility can provide useful tools for maintaining compatibility with other radars in the environment. Some or all of the radars whose characteristics are presented in Tables 1, 2, 3 and 4 possess these properties. Those Tables are extensive to exemplify the wide vari
35、ety of radar missions, platforms, waveforms, bandwidths, duty cycles, power levels, transmitter devices, etc. found in radars using this frequency band, although they do not illustrate the full repertoire of attributes that might appear in future systems. 4 Rec. ITU-R M.1796-2 TABLE 1 Characteristic
36、s of airborne radiodetermination radars operating in the frequency band 8 500-10 680 MHz Characteristics Units System A1 System A2 System A3 System A4 Function Search and track radar (multifunction) Airborne search radar Ground-mapping and terrain-following radar (multifunction)Track radar Tuning ra
37、nge MHz 9 300-10 000 8 500-9 600 9 240, 9 360 and 9 480 10 000-10 500 Modulation Pulse Pulse Non-coherent frequency-agile pulse-position modulation CW, FMCW Peak power into antenna kW 17 143 (min) 220 (max) 95 1.5 Pulse widths and pulse repetition rates s pps 0.285; 8 200 to 23 000 2.5; 0.5 400 and
38、1 600 0.3, 2.35, and 4 2 000, 425 and 250 Not applicable Maximum duty cycle 0.0132 0.001 0.001 1 Pulse rise/fall time s 0.01/0.01 0.02/0.2 0.1/0.1 Not applicable Output device Travelling wave tube Tunable magnetron Cavity-tuned magnetron Travelling wave tube Antenna pattern type Pencil Fan Pencil Pe
39、ncil Antenna type Planar array Parabolic reflector Flat-plate planar array Planar array Antenna polarization Linear Linear Circular Linear Antenna main beam gain dBi 32.5 34 28.3 35.5 Antenna elevation beamwidth degrees 4.6 3.8 5.75 2.5 Antenna azimuthal beamwidth degrees 3.3 2.5 5.75 2.5 Antenna ho
40、rizontal scan rate degrees/s 236 (118 scans/min) 36 or 72 (6 or 12 rpm) Up to 106 (Up to 53 scans/min) 90 Antenna horizontal scan type (continuous, random, sector, etc.) Sector: 60 (mechanical) 360 (mechanical) Sector: 60 (mechanical) Sector: 60 (mechanical) Rec. ITU-R M.1796-2 5 TABLE 1 (continued)
41、 Characteristics Units System A1 System A2 System A3 System A4 Antenna vertical scan rate degrees/s 118 (59 scans/min) Not applicable 148.42 (Up to 137 scans/min) 90 Antenna vertical scan type Sector: 60 (mechanical) Not applicable Sector: +25/40 (mechanical) Sector: 60 (mechanical) Antenna side-lob
42、e (SL) levels (1stSLs and remote SLs) dBi 7.5 at 15 Not specified 5.3 at 10 Not specified Antenna height Aircraft altitude Aircraft altitude Aircraft altitude Aircraft altitude Receiver IF 3 dB bandwidth MHz 3.1; 0.11 5 5.0, 1.8 and 0.8 0.48 Receiver noise figure dB Not specified Not specified 6 3.6
43、 Minimum discernible signal dBm 103 107; 101 101 Total chirp width MHz Not applicable Not applicable Not applicable Not specified RF emission bandwidth 3 dB 20 dB MHz 3.1; 0.11 22.2; 0.79 0.480; 2.7 1.5; 6.6 (Frequency and pulse width dependent) 100 to 118 102 to 120 Not specified Not specified 6 Re
44、c. ITU-R M.1796-2 TABLE 1 (continued) Characteristics Units System A5 System A6a(1)System A6b(1)Function Weather avoidance including wind-shear detection (navigation) Weather avoidance (WA), including wind-shear detection (WS) (navigation) Ground-mapping, including: Monopulse ground mapping (MGM) an
45、d Doppler beam sharpening (DBS) Tuning range MHz 9 330 9 305-9 410 WA: frequency agile pulse-to-pulse ( 2 000 hops/s); WS: adaptive single frequency 9 360 and 9 305-9 410 MGM: frequency agile pulse-to-pulse ( 600 hops/s); DBS: single frequency (9 360) Modulation Pulse WA: unmodulated and Barker-code
46、d (5:1 and 13:1) pulses; WS: unmodulated pulses MGM and DBS: Barker-coded (13:1) pulses Peak power into antenna W 150 150 150 Pulse width and Pulse repetition rate s pps 1 to 20 180 to 9 000 WA: 0.2-230; WS: 2 WA: 2 000 pps for 0.2-6 s pulses, decreasing to 230 pps for 230 s pulses; WS: 3 600-3 940
47、pps MGM: 1.3-260; DBS: 0.64-20 MGM: 600 pps for 1.3-60 s pulses, decreasing to 220 pps for 260 s pulses; DBS: 700-1 600 pps for all pulse widths Maximum duty cycle Not specified WA: 0.054; WS: 0.0076 MGM: 0.057; DBS: 0.033 (0.024 long term) Pulse rise/fall time s Not specified WA: 0.02-0.05/0.01; WS
48、: 0.02/0.01 MGM: 0.01-0.02/0.01-0.02; DBS: 0.02-0.04/0.01 Output device Solid state FET FET Antenna pattern type Pencil Pencil Fan Antenna type Planar array Planar array Planar array Antenna polarization Not specified Linear Linear Antenna main beam gain dBi 34.4 32 28.7 Antenna elevation beamwidth
49、degrees 3.5 4 42 Rec. ITU-R M.1796-2 7 TABLE 1 (continued) Characteristics Units System A5 System A6a(1)System A6b(1)Antenna azimuthal beamwidth degrees 3.5 2.7 2.7 Antenna horizontal scan rate degrees/s Not specified 200 ( 40 scans/min) 200 ( 40 scans/min) Antenna horizontal scan type (continuous, random, sector, etc.) Sector: 30 Sector: 15 to 135 (mechanical) Sector: 15 to 135 (mechanical) Antenna vertical scan rate Not specified 20 scans/min Not applicable Antenna vertical scan type (continuous, random, sector, etc.
