1、 Recommendation ITU-R M.1465-3 (01/2018) Characteristics of and protection criteria for radars operating in the radiodetermination service in the frequency range 3 100-3 700 MHz M Series Mobile, radiodetermination, amateur and related satellite services ii Rec. ITU-R M.1465-3 Foreword The role of th
2、e 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. T
3、he 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 serv
6、ice (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 coordina
7、tion 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. E
8、lectronic Publication Geneva, 2018 ITU 2018 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R M.1465-3 1 RECOMMENDATION ITU-R M.1465-3 Characteristics of and protection criteria for radars operating in the radio
9、determination service in the frequency range 3 100-3 700 MHz (2000-2007-2015-2018) Scope This Recommendation provides technical and operational characteristics, as well as protection criteria, of operational land/ship/air based radars in the frequency range 3 100-3 700 MHz1. The Recommendation inclu
10、des representative characteristics on the transmitter, receiver, and antenna components, as well as deployment information, of these radars. Keywords Characteristics, protection criteria, ship radar, ground-based radar, airborne radar Abbreviations/Glossary AMSL Above mean sea level ATC Air traffic
11、control CPFSK Continuous-phase frequency shift keying MTI Moving target indication PA Phased array SWA Slotted waveguide array Related ITU Recommendations, Reports Recommendation ITU-R M.1460 Technical and operational characteristics and protection criteria of radiodetermination radars in the freque
12、ncy band 2 900-3 100 MHz Recommendation ITU-R M.1461 Procedures for determining the potential for interference between radars operating in the radiodetermination service and systems in other services Recommendation ITU-R M.1464 Characteristics of radiolocation radars, and characteristics and protect
13、ion criteria for sharing studies for aeronautical radionavigation and meteorological radars in the radiodetermination service operating in the frequency band 2 700-2 900 MHz The ITU Radiocommunication Assembly, considering a) that antenna, signal propagation, target detection, and large necessary ba
14、ndwidth characteristics of radar to achieve their functions are optimum in certain frequency bands; b) that the technical characteristics of radars operating in the radiodetermination service are determined by the mission of the system and vary widely even within a frequency band; c) that the radion
15、avigation service is a safety service as specified by No. 4.10 of the Radio Regulations (RR) and harmful interference to it cannot be accepted; 1 Some systems operate in the frequency band extending down to 2 800 MHz. 2 Rec. ITU-R M.1465-3 d) that representative technical and operational characteris
16、tics of systems operating in frequency bands allocated to the radiodetermination service are required to determine the feasibility of introducing new types of systems; e) that procedures and methodologies are needed to analyse compatibility between radars operating in the radiodetermination service
17、and systems in other services; f) that the frequency band 3 100-3 400 MHz is allocated to the radiolocation service on a primary basis in all three Regions; g) that the frequency band 3 400-3 600 MHz is allocated to the radiolocation service on a secondary basis in Region 1; h) that the frequency ba
18、nd 3 400-3 600 MHz is allocated to the radiolocation service on a primary basis in Regions 2 and 3 under No. 5.433 of the RR; i) that the frequency band 3 600-3 700 MHz is allocated to the radiolocation service on a secondary basis in Regions 2 and 3; j) that the frequency band 3 100-3 300 MHz is al
19、so allocated to the radionavigation service on a primary basis in the countries listed in No. 5.428 of the RR; k) that Recommendation ITU-R M.1464 contains characteristics of some systems operating in the frequency range 2 700-3 400 MHz, recognizing that RR Nos. 5.433, 5.429, 5.429A, 5.429B, 5.429C,
20、 5.429D, 5.429E and 5.429F apply, recommends 1 that the technical and operational characteristics of the radiolocation radars described in Annex 1 should be considered representative of those operating in the frequency range 3 100-3 700 MHz; 2 that Recommendation ITU-R M.1461 should be considered in
21、 analysing compatibility between radars operating in the radiodetermination service with systems in other services; 3 that the criterion of interfering signal power to radar receiver noise power level, I/N, of 6 dB should be used as the required protection level for the radiolocation systems, and th
22、at this represents the net protection level if multiple interferers are present. Annex 1 Technical and operational characteristics of radiolocation radars operating in the frequency range 3 100-3 700 MHz 1 Introduction The characteristics of radiolocation radars operating in the frequency range 3 10
23、0-3 700 MHz are presented in Table 1, and are discussed further in the following paragraphs. Rec. ITU-R M.1465-3 3 TABLE 1 Table of characteristics of radiolocation systems in the frequency range 3 100-3 700 MHz2, 3 Parameter Units Land-based systems Ship systems Airborne system L-A L-B L-C L-D L-E
24、S-A S-B S-C S-D A-A Use Surface and air search Surface search Multi-function Surface and air search Multi-function surface and air search Multi-function surface and air search Surface and air search Surface and air search Modulation P0N/Q3N P0N P0N/Q7N P0N/Q7N Q0N P0N Q7N P0N/Q7N Q7N Q7N Tuning rang
25、e GHz 3.1-3.7 2.8-3.4 2.9-3.5 3.3-3.4 2.9-3.7 3.1-3.5 3.1-3.7 Tx power into antenna (Peak) kW 640 1 000 200 60-70 0.33 1 000 4 000-6 400 60-200 4-90 1 000 Pulse width s 160-1 000 1.0-15 50-500 3-150 0.65 0.25, 0.6 6.4-768 0.1-1000 0.1-100 1.25(1) Repetition rate kHz 0.020-2 0.536 0.2-50 0.8-50 160 1
26、.125 0.152-6.0 0.3-10 0.5-10 2 Compression ratio 48 000 Not applicable Up to 1 000 Up to 2 000 26 Not applicable 64-512 Up to 20 000 Up to 400 250 Type of compression Not available Not applicable LFM its tuning range is the same as the transmitter. The System S-B receiver operates in the frequency r
27、ange 2 900-3 700 MHz. The receiver characteristics are not available but are assumed to be modern receivers with much processing gain needed to detect multiple and varied objects at extended ranges, in heavy clutter and in adverse weather. 2.2.4 Antenna System S-A uses a mechanically rotating reflec
28、tor type antenna with an azimuth beamwidth of 1.75 and csc2 beam in elevation from 4.4 to 30 with a mainbeam gain of 32 dBi. The nominal antenna height is 46 m above mean sea level (AMSL). System S-B uses four planar electronically-steered phased-array antennas to provide 360 coverage with a mainbea
29、m gain of 42 dBi. The nominal height of the Radar S-B antenna is 20 m AMSL. 2.3 Airborne radar Airborne radars found in this frequency band take advantage of the spectrum properties found at this wavelength to conduct long-range surveillance, target tracking and ATC. The spectrum characteristics for
30、 typical airborne radar found in this frequency band are depicted in Table 1. This system is a multifunction, phased-array radar that is deployed on surveillance aircraft of a number of administrations. The antenna of this system is a large, slotted waveguide array assembly mounted atop of the airfr
31、ame. It provides 40 dBi mainbeam gain and its sidelobe gain has been estimated to be 10 dBi. The aircraft carrying these radars are capable of worldwide operations. In addition to their air surveillance and ATC functions they also have a sea surveillance mode. This airborne system is typically opera
32、ted at about 9 000 m in altitude and can be operated for extended hours of up to 12 h depending upon aircrew availability. In some situations constant surveillance is maintained on a 24 h per day basis by replenishment aircraft. 8 Rec. ITU-R M.1465-3 3 Protection criteria Radars are affected in fund
33、amentally different ways by unwanted signals of different forms, and an especially sharp difference prevails between the effects of continuous noise-like energy and those of pulses. Systems which use pulse compression have their IF bandwidth matched to the compressed pulse and act as a matched filte
34、r for minimum S/N degradation. Pulse compression filters may be partially matched to and hence increase the effect of noise-like interference. In that case, an I/N ratio of 6 dB may not be adequate, and further studies or compatibility measurements may be necessary to assess the interference in term
35、s of the operational impact on the radars performance. Continuous-wave interference of a noise-like type inflicts a desensitizing effect on radiodetermination radars, and that effect is predictably related to its intensity. Within any azimuth sectors in which such interference arrives, its power spe
36、ctral density can, to a reasonable approximation, simply be added to the power spectral density of the radar-system thermal noise. If the power of radar-system noise in the absence of interference is denoted by N and that of noise-like interference by I, the resultant effective noise power becomes s
37、imply I + N. Given that the radar protection criteria traditionally established within ITU-R are based on the penalties incurred to maintain the target-return signal-to-noise ratio in the presence of the interference, requiring that the target-return power be raised in proportion to the increase of
38、noise power from N to I + N. That can only be done by accepting shorter maximum ranges on given targets, sacrificing observation of small targets, or modifying the radar to give it a higher transmitter power or power-aperture product. (In modern radars, receiving-system noise is usually already near
39、 an irreducible minimum and nearly-optimum signal processing is becoming commonplace.) These penalties vary depending on the radars function and the nature of its targets. For most radar systems, an increase in the effective noise level of about 1 dB would inflict the maximum tolerable degradation o
40、n performance. In the case of a discrete target having a given average or median radar cross section (RCS), that increase would reduce the detection range by about 6% regardless of any RCS fluctuation characteristics that target might have. This effect results from the fact that the achievable free-
41、space range is proportional to the fourth root of the resultant signal-to-noise power ratio (SNR), from the most familiar form of the radar range equation. A 1 dB increase of effective noise power is a factor of 1.26 in power, so it would, if uncompensated, require the free-space range from a given
42、discrete target to be reduced by a factor of 1/(1.26)1/4), or 1/1.06; i.e. a range capability reduction of about 6%. In the range equation, the SNR is also directly proportional to transmitter power, to power-aperture product (for a surveillance radar), and to target radar cross section. Alternative
43、ly, therefore, the 1 dB increase of effective noise power could be compensated by forgoing detection of targets except those having an average radar cross section 1.26 times as large as the minimum-size target that could be detected in the interference-free regime or by increasing the radar transmit
44、ter power or its power-aperture product by 26%. Any of these alternatives is at the limit of acceptability in most radar missions, and the system modifications would be costly, impractical, or impossible, especially in mobile radars. For discrete targets, those performance penalties hold for any given probability of detection and false-alarm rate and any target fluctuation characteristics.
