1、 Recommendation ITU-R M.1478-3 (09/2014) Protection criteria for Cospas-Sarsat search and rescue instruments in the band 406-406.1 MHz M Series Mobile, radiodetermination, amateur and related satellite services ii Rec. ITU-R M.1478-3 Foreword The role of the Radiocommunication Sector is to ensure th
2、e 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. The regulatory and policy functions of the R
3、adiocommunication 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 for ITU-T/ITU-R/ISO/IEC referenced in Anne
4、x 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 ITU-T/ITU-R/ISO/IEC and the ITU-R patent i
5、nformation 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 service (sound) BT Broadcasting service (televi
6、sion) 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 coordination between fixed-satellite and fixed serv
7、ice 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. Electronic Publication Geneva, 2014 ITU 2014
8、 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R M.1478-3 1 RECOMMENDATION ITU-R M.1478-3 Protection criteria for Cospas-Sarsat search and rescue instruments in the band 406-406.1 MHz (2000-2004-2011-2014) Sco
9、pe This Recommendation provides protection criteria for Cospas-Sarsat search and rescue instruments placed on-board satellites in geostationary, medium-Earth and low-Earth orbits (LEO) and receiving signals from emergency position indicating radio beacons (EPIRBs) and other distress beacons operatin
10、g in the 406-406.1 MHz band. Keywords Cospas-Sarsat; protection criteria; search and rescue instruments; 406-406.1 MHz. Abbreviations/Glossary EPIRBs - emergency position indicating radio beacons DRU - data recovery unit GOES - geostationary operational and environmental satellites MSG - METEOSAT se
11、cond generation SARP - search and rescue processor SARR - search and rescue repeaters Related ITU Recommendations, Reports Recommendation ITU-R M.1731-2 Protection criteria for Cospas-Sarsat local user terminals in the band 1 544-1 545 MHz Recommendation ITU-R M.1787-2 Description of systems and net
12、works in the radionavigation-satellite service (space-to-Earth and space-to-space) and technical characteristics of transmitting space stations operating in the bands 1 164-1 215 MHz,1 215-1 300 MHz and 1 559-1 610 MHz The ITU Radiocommunication Assembly, considering a) that the Cospas-Sarsat global
13、 satellite-based search and rescue system operates within an exclusive allocation in the band 406-406.1 MHz; b) the analysis provided in Annex 1 concerning maximum allowable spectral power flux-density (spfd) requirements of the Sarsat Search and Rescue Processor (SARP) against broadband out-of-band
14、 emissions and the upper bound on Doppler frequency shift associated with MSS transmissions received by Sarsat; c) the analysis provided in Annex 2 concerning maximum allowable power flux-density (pfd) requirements for the Sarsat SARP against narrow-band spurious emissions; d) that Annex 3 provides
15、guidelines for using the protection requirements of the 406-406.1 MHz band for the Sarsat SARP instruments (on-board satellite equipment); 2 Rec. ITU-R M.1478-3 e) that Annex 4 provides guidelines for protection of the primary safety services allocated in the band 406-406.1 MHz (C-S system) from non
16、-GSO mobile-satellite service (MSS) downlink emissions below 406 MHz; f) that Annexes 5, 6 and 7 provide guidelines for the protection of 406-406.1 MHz search and rescue repeaters (SARR) on Sarsat LEO satellites, geostationary operational and environmental satellites (GOES) and meteosat second gener
17、ation (MSG) satellites respectively; g) that Annexes 8 and 9 provide guidelines for the protection of 406-406.1 MHz search and rescue repeaters (SARR) on geostationary satellites (Electro) and navigational satellites (GLONASS) respectively; h) that Annex 10 provides guidelines for the protection of
18、406-406.1 MHz search and rescue repeaters (SARR) on navigational satellites (Galileo); i) that Annex 11 provides an overall synthesis of the characteristics of all instruments in current and future operation on board the various types of satellites in LEO, MEO or GSO orbits, recommends 1 that analys
19、is to determine the effect upon Sarsat SARP instruments by systems using adjacent frequency bands should be based upon a maximum acceptable spfd at the Sarsat antenna of 198.6 dB(W/(m2 Hz); 2 that analysis to determine the effect upon the Sarsat SARP instruments from narrow-band spurious emissions (
20、e.g. harmonic emissions, parasitic emissions, intermodulation products and frequency conversion products) should be based upon a maximum pfd of 166.2 dB(W/m2) at the Sarsat antenna within a resolution bandwidth of 19 Hz; 3 that analysis to determine the effect upon Cospas SARP instruments by systems
21、 using adjacent frequency bands should be based upon a maximum acceptable spfd at the Cospas antenna of 198.6 dB(W/(m2 Hz); 4 that analysis to determine the effect upon the Cospas SARP instruments from narrow-band spurious emissions (e.g. harmonic emissions, parasitic emissions, intermodulation prod
22、ucts and frequency conversion products) should be based upon a maximum pfd of 170.6 dB(W/m2) at the Cospas antenna within a resolution bandwidth of 40 Hz; 5 that analysis to determine the effect upon Cospas-Sarsat non-GSO instruments by proposed MSS systems using the 405-406 MHz frequency band shoul
23、d utilize an upper bound Doppler shift of 20 kHz; 6 that analysis to determine the effect upon Sarsat LEO repeaters by systems using adjacent frequency bands should be based on a maximum spfd at the Sarsat antenna of 181.3 dB (W/(m2 Hz); 7 that analysis to determine the effect upon GOES GEO repeater
24、s by systems using adjacent frequency bands should be based on a maximum spfd at the Sarsat antenna of 201.1 dB (W/(m2 Hz); 8 that analysis to determine the effect upon MSG GEO repeaters by systems using adjacent frequency bands should be based on a maximum spfd at the Sarsat antenna of 206.4 dB (W/
25、(m2 Hz); 9 that analysis to determine the effect upon Electro GEO repeaters by systems using adjacent frequency bands should be based on a maximum spfd at the Cospas antenna of 198.7 dB (W/(m2 Hz); Rec. ITU-R M.1478-3 3 10 that analysis to determine the effect upon GLONASS MEO repeaters by systems u
26、sing adjacent frequency bands should be based on a maximum spfd at the Cospas antenna of 205.2 dB (W/(m2 Hz); 11 that analysis to determine the effect upon Galileo MEO repeaters by systems using adjacent frequency bands should be based on a maximum spfd at the antenna of 206.1 dB (W/(m2 Hz); 12 that
27、 analysis to determine the effect upon the Galileo MEO repeaters from narrow-band spurious emissions should be based upon a maximum pfd of 166.2 dB(W/m2) at the antenna. Annex 1 Protection criteria for Cospas-Sarsat in the band 406-406.1 MHz against out-of-band broadband emissions 1 Introduction Thi
28、s Annex provides information relating to the C-S system and its protection requirements from broadband out-of-band emissions. 2 Background Other ITU texts provide substantial information concerning the following items: parameters of several non-GSO MSS networks; pfd threshold level of interference;
29、search and rescue (SAR) protection using spectral shaping or filtering techniques. 3 spfd threshold level of interference The addition of broadband noise to the Sarsat SARP will have the effect of increasing the system bit error ratio (BER), and therefore adversely affect its performance. As identif
30、ied in ITU-R studies the maximum acceptable uplink BER for the Sarsat SARP cannot exceed 5 105. Based upon this requirement, this analysis identifies the maximum acceptable pfd associated with broadband noise in the Sarsat SARP uplink channel. The analysis does not address the effect of narrow-band
31、emissions (e.g. spectral lines), which will also adversely affect the SARPs performance nor does it address the protection requirements for all C-S instruments (e.g. Sarsat search and rescue repeater, Cospas SARP). Figure 1 shows the main hardware elements on board the NOAA satellites (and on the fu
32、ture METOP satellites). 4 Rec. ITU-R M.1478-3 FIGURE 1 On-board hardware equipment M .1 4 7 8 -0 1A t t e nu a t i on : 1 .6 d B S A R PS a r s a t SA R Pr e c e i ve a nt e nn a ( U D A )pf d A BThe UDA antenna gain pattern specification is expressed according to the nadir angle in Table 1: TABLE 1
33、 SARP receive antenna (UDA) gain pattern The specified figures in Table 1 are of the 406 MHz-Sarsat receive antenna pattern for the SARP, as they should be for the NOAA and METOP satellites. The Sarsat typical figures are: noise figure = 2.5 dB (C-S SARP input parameter), nominal background noise te
34、mperature = 1 000 K (C-S input parameter), attenuation between the antenna and the SARP receiver = 1.6 dB. Thus, the system noise temperature at the input of the SARP receiver (point B on Fig. 1) equals 1 010 K and therefore, the noise spectral density equals N0 = 198.6 dB(W/Hz). The worst-case spec
35、ification states that the SARP is designed to operate correctly when the received signal has a power C = 161 dBW (minimum level of the received signal) at the input of the receiver, which provides an effective Eb/N0 = 9.1 dB in the bit detector of the SARP if we take into account the beacon waveform
36、 and the various losses. In this case, the corresponding BER equals 2.6 105. Therefore, in order to achieve a BER of 5 105 (which is an approximate doubling of the BER) the maximum acceptable degradation is 0.3 dB. At Eb/N0 = 8.8 dB, the BER equals 4.8 105. Hereunder, the additive noise correspondin
37、g to the 0.3 dB degradation for the C/N0 is calculated. Let I0 represent the additive noise power density coming from the non-GSO MSS interferers. The initial N0 noise becomes N0 + I0. The signal-to-noise ratio C/N0 becomes C/(N0 + I0). The degradation is 0.3 dB = 10 log (C/N0)/(C/(N0 + I0), thus I0
38、/N0 = 11.5 dB and I0 = 210.1 dB(W/Hz) which corresponds to a temperature of 70.8 K, and therefore an increase of 7% of the system noise temperature at the input of the SARP receiver. Nadir satellite angle 62 59 54 47 39 31 22 13 5 0 Gain in RHCP 3.85 3.54 2.62 1.24 0.17 1.33 2.24 3.08 3.80 3.96 Gain
39、 in LHCP 5.69 6.23 7.52 9.39 11.39 13.12 14.52 15.77 17.17 18.00 Axial ratio 6.02 5.85 5.59 5.26 4.90 4.57 4.31 4.11 3.78 3.49 Rec. ITU-R M.1478-3 5 Therefore, the maximum admissible level of noise density is I0 = 210.1 dB(W/Hz) (calculated for point B in Fig. 1). As shown in Fig. 1, the noise densi
40、ty, I0, takes into account the attenuation and the antenna gain. As the spfd is required, it is necessary to transform this figure in dB(W/(m2 Hz). The equivalent surface area of an antenna having a gain G is 42GS . Therefore, the corresponding spfd equals 210 + 1.6 (losses) 10 log10 S = 198.6 dB(W/
41、(m2 Hz), taking into account the highest satellite nadir angle. The maximum level of broadband noise interference in the band 406-406.1 MHz shall not exceed 198.6 dB(W/(m2 Hz) to protect the Sarsat SARP instrument. 4 Upper bound on Doppler shift Any proposed protection bandwidth should also account
42、for the Doppler shifts. The value of the maximum Doppler shift must be carefully examined. The worst case occurs when the Sarsat and the non-GSO MSS satellites are located on the same orbit and travel in opposite directions. In this case, the analysis below applies. The non-GSO MSS signal comes from
43、 point A. The Sarsat satellite is represented by point B. The Sarsat satellite is moving at a speed VB. If the non-GSO MSS satellite is not moving, the received frequency at B is )1( cVF BABF in the worst case. On the other hand, the received frequency at B has the same value if the Sarsat satellite
44、 is not moving and if the non-GSO MSS satellite is moving. If the altitude of the satellite equals 850 km, its speed is 7 426 m/s. As the two satellites are moving in opposite directions, the upper bound Doppler shift equals: kH z202 cVF BA This is a worst-case situation and is not necessarily appli
45、cable to all the proposed MSS systems. 5 Conclusions and recommendations Following the above computations, the conclusions and recommendations regarding the impact of emissions from adjacent frequency bands on the Sarsat SARP are: the maximum level of broadband noise interference in the band 406-406
46、.1 MHz shall not exceed 198.6 dB(W/(m2 Hz) to protect the Sarsat SARP instrument; the upper bound on Doppler shift is 20 kHz; it is recommended that further analyses be conducted to determine the impact on C-S from MSS occupying the 405-406 MHz band using an spfd of 198.6 dB(W/(m2 Hz), an appropriat
47、e Doppler shift and accounting for the worst-case scenario associated with the entire MSS constellation as envisaged. 6 Rec. ITU-R M.1478-3 Annex 2 Protection criteria for C-S system in the band 406-406.1 MHz against narrow-band spurious emissions 1 Introduction This Annex provides information relat
48、ing to the C-S system and its protection requirements against narrow-band spurious emissions. 2 Background Annex 1 contains the protection criteria for Sarsat SARP in the band 406-406.1 MHz to be used as a basis for analysis of interference from out-of-band emissions. This Annex provides protection
49、requirements for the Sarsat SARP instrument in respect of interference from narrow-band spurious emissions (harmonic emissions, parasitic emissions, intermodulation products and frequency conversion products). The terminology used in this Annex is derived from Recommendation ITU-R SM.328 Spectra and bandwidth of emissions, and from Recommendation ITU-R SM.329 Unwanted emissions in the spurious domain. This Annex addresses protection criteria for only Sarsat SARP instrume
