1、 Recommendation ITU-R M.1902(01/2012)Characteristics and protection criteriafor receiving earth stations in the radionavigation-satellite service(space-to-Earth) operatingin the band 1 215-1 300 MHzM SeriesMobile, radiodetermination, amateurand related satellite servicesii Rec. ITU-R M.1902 Foreword
2、 The role 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
3、 are adopted. 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 Commo
4、n Patent 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 Pa
5、tent Policy 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 Br
6、oadcasting 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 shari
7、ng and coordination 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 Resolu
8、tion ITU-R 1. Electronic Publication Geneva, 2012 ITU 2012 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R M.1902 1 RECOMMENDATION ITU-R M.1902 Characteristics and protection criteria for receiving earth stati
9、ons in the radionavigation-satellite service (space-to-Earth) operating in the band 1 215-1 300 MHz (Questions ITU-R 217-2/4 and ITU-R 288/4) (2012) Scope Characteristics and protection criteria for radionavigation-satellite service (RNSS) receiving earth stations operating in the band 1 215-1 300 M
10、Hz are presented in this Recommendation. This information is intended for performing analyses of radio-frequency interference impact on RNSS (space-to-Earth) receivers operating in the band 1 215-1 300 MHz from radio sources other than in the RNSS. The ITU Radiocommunication Assembly, considering a)
11、 that systems and networks in the radionavigation-satellite service (RNSS) provide worldwide accurate information for many positioning, navigation and timing applications, including safety aspects for some frequency bands and under certain circumstances and applications; b) that any properly equippe
12、d earth station may receive navigation information from systems and networks in the RNSS on a worldwide basis; c) that Recommendation ITU-R .1787 provides technical descriptions of systems and networks in the RNSS and technical characteristics of transmitting space stations operating in the bands 1
13、164-1 215 MHz, 1 215-1 300 MHz and 1 559-1 610 MHz; d) that Recommendation ITU-R .1904 provides technical characteristics and protection criteria of receiving space stations operating in the RNSS (space-to-space) in the bands 1 164-1 215 MHz, 1 215-1 300 MHz and 1 559-1 610 MHz; e) that Recommendati
14、on ITU-R M.1463 contains system characteristics for radiodetermination systems in the 1 215-1 400 MHz band; f) that Recommendation ITU-R M.1901 provides guidance on this and other ITU-R Recommendations related to systems and networks in the RNSS operating in the frequency bands 1 164-1 215 MHz, 1 21
15、5-1 300 MHz, 1 559-1 610 MHz, 5 000-5 010 MHz and 5 010-5 030 MHz, recognizing a) that the band 1 215-1 300 MHz is allocated on a primary basis to the Earth exploration-satellite service (EESS) (active), radiolocation service, RNSS (space-to-Earth and space-to-space) and space research service (acti
16、ve) in all three Regions; b) that in a number of countries the band 1 215-1 300 MHz also contains primary allocations to the fixed and mobile services, and/or to the radionavigation service (limited in some cases to aeronautical radionavigation use in a portion of the band); c) that No. 5.329 of the
17、 Radio Regulations (RR) states: “Use of the radionavigation-satellite service in the band 1 215-1 300 MHz shall be subject to the condition that no harmful interference is caused to, and no protection is claimed from, the radionavigation service authorized under RR No. 5.331. Furthermore, the use of
18、 the radionavigation-satellite service in the band 2 Rec. ITU-R M.1902 1 215-1 300 MHz shall be subject to the condition that no harmful interference is caused to the radiolocation service. RR No. 5.43 shall not apply in respect of the radiolocation service. Resolution 608 (WRC-03) shall apply”; d)
19、that RR No. 5.332 states that EESS (active) in the band 1 215-1 260 MHz shall not cause harmful interference to RNSS, noting that Recommendation ITU-R RS.1749 contains characteristics for various space-borne synthetic aperture radars in the band 1 215-1 300 MHz and Recommendation ITU-R RS.1347 recom
20、mends that sharing be considered feasible in the band 1 215-1 260 MHz between space-borne synthetic aperture radars and RNSS based on demonstrations including ground compatibility testing, recommends 1 that the characteristics and protection criteria of receiving earth stations given in Annex 1 shou
21、ld be used in performing analyses of the interference impact on RNSS (space-to-Earth) receivers operating in the band 1 215-1 300 MHz from radio sources other than in the RNSS. Annex 1 Technical characteristics and protection criteria for receiving earth stations in the RNSS (space-to-Earth) operati
22、ng in the band 1 215-1 300 MHz 1 Introduction Several classes of receivers that vary in terms of function and performance are likely to use the RNSS satellite signals in the 1 215-1 300 MHz frequency band. The sections below include a general description of each type of RNSS receiver and a descripti
23、on of the receiver characteristics and protection criteria. Several of the receivers described are multiple-frequency band receiver types that use or plan to use RNSS signals simultaneously for this and one or more other RNSS bands. 2 RNSS receiver application descriptions This section describes sev
24、eral types of current and prospective RNSS receivers. 2.1 Satellite-based augmentation system1ground reference receiver This ground-based receiver type is used in satellite-based augmentation system (SBAS) ground network operations to determine ionospheric delays and RNSS signal integrity. The recei
25、ver uses a semi-codeless technique that exploits a unique feature enabled by the particular RNSS signal architecture whereby the L1 and L2 P(Y) signals are tracked, aided by the knowledge of dynamic 1 SBAS is a means for providing RNSS regional measurement error correction and integrity data via GSO
26、 satellite signals. Rec. ITU-R M.1902 3 carrier phase obtained from L1 C/A2code and carrier tracking, and the knowledge of the average encryption clocking rate. This cross-correlation technique provides the capability to measure the signal delay at L2, thus making it possible to determine the signal
27、 delay variations due to the ionosphere. The cross-correlation scheme is made possible in part by the fact that the L1 and L2 P(Y) signals have identical codes. This receiver must also acquire and track SBAS satellite signals at the same frequency as the L1 C/A carrier. Semi-codeless receivers are m
28、ore sensitive to interference because they operate without benefit of knowing the Y code3. Acquisition is performed using the L1 C/A code signal. Acquisition at L2 is not applicable for this type of receiver. The characteristics and protection criteria for this receiver are provided in Table 1-1, co
29、lumn 1. Since the receiver uses L1 C/A and P(Y) signals simultaneous with L2 P(Y), it is also susceptible to interference in the band 1 559-1 610 MHz. Protection criteria and other characteristics for the SBAS ground reference receiver in that frequency band are specified in Recommendation ITU-R M.1
30、903. SBAS ground reference receivers serve critical roles, such as integrity monitoring of RNSS systems, at SBAS ground stations in known fixed locations. Hence appropriate protection to ensure continuous uninterrupted access to RNSS signals exists for these receivers, such as, but not limited to, p
31、hysical buffer zones. 2.2 RNSS semi-codeless receivers 2.2.1 High-precision semi-codeless receivers High-precision semi-codeless receivers are used primarily for surveying and other precise positioning applications (e.g. precision agriculture, scientific) where measurements of ionospheric delay are
32、required. Similar to the SBAS ground reference receiver above, these semi-codeless receivers use a technique whereby the L1 and L2 P(Y) signals are tracked, aided by the knowledge of dynamic carrier phase obtained from L1 C/A code tracking. There are two basic methods for this: 1) L1 and L2 P(Y) sig
33、nals are cross-correlated, or 2) the signals are actually independently tracked. High-precision receivers acquire and track RNSS signals in two or three frequency bands for proper operation and require protection in all bands used. There are also variations to these methods or combinations of the tw
34、o methods. In any case, the purpose is to provide an estimate of the ionospheric delay or an independent set of carrier phase measurements that support rapid removal of wavelength ambiguities, even when the receiver is in motion. This process provides improved position accuracy. The cross-correlatio
35、n scheme is made possible by the fact that L1 and L2 have identical, nearly synchronized P(Y) codes. The L2 P(Y) signal codes are delayed through the ionosphere relative to the L1 P(Y) signal codes, and also accompanied by carrier phase advances. The L1 P(Y) signal has the identical code and carrier
36、 Doppler as the L1 C/A signal, which allows the ability to aid the semi-codeless tracking using very narrow bandwidth tracking loops. This receiver will have characteristics similar to the SBAS ground reference receiver described above, but may differ in its susceptibility to interference. The chara
37、cteristics of this type of receiver are provided in Table 1-1, column 2. Since this receiver also uses 1 559-1 610 MHz band signals, it is susceptible to interference in that band. Protection criteria and other characteristics in the 1 559-1 610 MHz band specified for the CDMA-type high-precision re
38、ceiver are found in Recommendation ITU-R M.1903. 2 The L1 C/A and L1 P(Y) signals are in the 1 559-1 610 MHz RNSS frequency band while L2 P(Y) signals are in the 1 215-1 300 MHz RNSS band. Further details for these signals are found in Annex 2 (GPS) of Recommendation ITU-R M.1787. 3 Y code is a modi
39、fied and encrypted P code, having the same chipping rate and modulation characteristics as that of the P code. 4 Rec. ITU-R M.1902 2.2.2 L2C-transitional high-precision semi-codeless receivers This receiver has all the characteristics of the high-precision semi-codeless receiver in section 2.2.1 and
40、 also acquires and tracks the new L2C signal4on the L2 carrier received from available later-generation satellites. This receiver will use the semi-codeless technique described above to acquire and track L2 P(Y) signals on other earlier-generation satellites, and may use that technique on L2 P(Y) si
41、gnals received from the later-generation satellites as well, at least to provide calibration information for the hybrid L2C/L2 P(Y) operations. This hybrid operation requires that the phase difference between the L2C and L2 P(Y) signals is known. The L2C signal provides more robustness than availabl
42、e with the L2 P(Y) semi-codeless operation that is beneficial in more stressed environments. However, since receivers with this capability are used in system applications that also use the legacy L2 P(Y) semi-codeless receivers, in general, this extra robustness is not always available. Thus, the th
43、reshold interference power levels specified in Table 1-1, column 2 still apply. 2.3 High-precision receivers using L2C This receiver type is a ground-based receiver that will acquire and track the L2C signal, but not necessarily the L2 P(Y) signal. The function of this receiver is the same as the fu
44、nction of the high-precision semi-codeless receiver described above, but with more robustness gained from acquiring and tracking the L2C signal. This receiver type acquires and tracks the new L2C code received from certain later-generation satellites. This receiver may also use the semi-codeless tec
45、hnique described above to acquire and track L2 P(Y) signals from these and other satellites as well, at least to provide calibration information for the hybrid L2C/L2 P(Y) operations. This hybrid operation requires that the phase difference between the L2C and L2 P(Y) signals is known. The character
46、istics of this type of receiver that acquires and tracks the L2C signal are provided in Table 1-1, column 3. The L2C signal provides more robustness than available with the L2 P(Y) semi-codeless operation that is beneficial in more stressed environments. However, since receivers with this capability
47、 are used in system applications that also use the legacy L2 P(Y) semi-codeless receivers, in general, this extra robustness is not always available. Thus, the threshold interference power levels specified in column 2 of Table 1-1 also apply. 2.4 Air-navigation receiver Air-navigation refers to an a
48、irborne receiver designed for use from en-route through precision approach. This receiver type uses FDMA RNSS signals5and operates on several carrier frequencies simultaneously. Characteristics of this receiver type are specified in Table 1-1, column 4. Characteristics for the FDMA air-navigation re
49、ceivers may also apply to receivers developed for land and maritime applications that are not described in this Annex. 4 Further details of the L2C signal are found in Annex 2 (GPS) of Recommendation ITU-R M.1787. 5 The phrase “FDMA RNSS signals” refers to a technique in which all the RNSS satellites use the same modulation code, but each satellite transmits on a different carrier frequency. Further signal details are contained in Annex 1 (GLONASS) of Recommendation ITU-R M.1787. Rec. ITU-R M.1902 5 2.5 Indoor positioning The indoor positioning category represents RNSS receivers intended
