1、 Rec. ITU-R RS.1029-2 1 RECOMMENDATION ITU-R RS.1029-2*Interference criteria for satellite passive remote sensing (1994-1997-2003) The ITU Radiocommunication Assembly, considering a) that certain frequency bands, including some absorption bands of atmospheric gases (e.g. O2(oxygen) and H2O (water va
2、pour), have been allocated for spaceborne passive microwave remote sensing; b) that some of these bands are also allocated to other radio services; c) that performance criteria for satellite passive remote sensing are contained in Recommendation ITU-R RS.1028; d) that interference criteria should be
3、 compatible with performance objectives; e) that interference criteria are a necessary prerequisite to the establishment of sharing criteria; f) that interference criteria can be stated in terms of interference power within a reference bandwidth; g) that passive microwave remote sensing is performed
4、 in absorption bands to obtain important three-dimensional atmospheric data that are used in particular to initialize numerical weather prediction (NWP) models; h) that studies have established that measurements in absorption bands are extremely vulnerable to interference because, in general, there
5、is no possibility to detect and to reject data that are contaminated by interference, and because propagation of undetected contaminated data into NWP models may have a destructive impact on the reliability/quality of weather forecasting; j) that three-dimensional measurements of atmospheric tempera
6、ture or gas concentration are performed in the absorption bands including those in the range 52.6-59.3 GHz, 115.25-122.25 GHz, 174.8-191.8 GHz, as well as the auxiliary window channels at 23.6-24 GHz, 31.3-31.8 GHz, 50.2-50.4 GHz and 86-92 GHz; k) that the sensitivities of radiometric passive sensor
7、s are generally expressed as a temperature differential, Te, given by: tBTTse/= K where: Te: radiometric resolution (r.m.s. uncertainty in estimation of total system noise, Ts) : receiver system constant Ts: system noise temperature (K) (antenna temperature and receiver noise temperature) B : spectr
8、al resolution (of spectroradiometer) or “reference bandwidth” of a single radiometric channel (Hz) t : sensor integration time (s); *Radiocommunication Study Group 7 made editorial amendments to this Recommendation. 2 Rec. ITU-R RS.1029-2 l) that the radiometer threshold, or minimum discernible powe
9、r change, is given by: BTkPe= W where k is Boltzmanns constant = 1.38 1023J/K, recommends 1 that the interference level for spaceborne passive sensors in the bands in Table 1 should be set at 20% of P; 2 that permissible interference levels and reference bandwidths for the frequency bands preferred
10、for passive sensing of the Earths land, oceans and atmosphere as specified in Table 1 should be used in any interference assessment or sharing studies; 3 that the interference level in Table 1 should not be exceeded for more than a percentage of sensor viewing area or a percentage of measurement tim
11、e as given in column 5 of Table 1. TABLE 1 Interference criteria for passive remote sensing of environmental data Frequency band(s)(1) (GHz) Total bandwidth required (MHz) Reference bandwidth (MHz) Maximum interference level (dBW) Percentage of area or time permissible interference level may be exce
12、eded(2)(%) Scan mode (N, L)(3)1.37-1.4s, 1.4-1.427P 100 27 174 0.1 N 2.64-2.655s, 2.655-2.69s, 2.69-2.7P 45 10 176 0.1 N 4.2-4.4s, 4.95-4.99s 200 200 158/166(4)0.1 N 6.425-7.25 200 200 158/166(4)0.1 N 10.6-10.68p, 10.68-10.7P 100 100 156/166(4)0.1 N 15.2-15.35s, 15.35-15.4P 200 50 169 0.1 N 18.6-18.
13、8p 200 200 153/163(4)5/0.1(4) N 21.2-21.4p 200 100 163/169(4)1/0.1(4)N 22.21-22.5p 300 100 160/169(4)1/0.1(4)N 23.6-24P 400 200 166 0.01 N 31.3-31.5P, 31.5-31.8p 500 200 160/166(4)0.01 N Rec. ITU-R RS.1029-2 3 TABLE 1 (continued) Frequency band(s)(1) (GHz) Total bandwidth required (MHz) Reference ba
14、ndwidth (MHz) Maximum interference level (dBW) Percentage of area or time permissible interference level may be exceeded(2)(%) Scan mode (N, L)(3)36-37p 1 000 100 156/166(4)0.1 N 50.2-50.4P 200 200 166 0.01 N 52.6-54.25P, 54.25-59.3p 6 700(5)100 161/169(4)0.01 N 86-92P 6 000 100 169 0.01 N 100-102P
15、2 000 10 189 1 L 109.5-111.8P 2 000 10 189 1 L 114.25-116P 1 750 10 189 1 L 115.25-116P, 116-122.25p 7 000(5)200/10(6) 166/189(6) 0.01/1(6) N, L 148.5-151.5P 3 000 500/10(6) 159/189(6) 0.01/1(6) N, L 155.5-158.5(7)p 3 000 200 163 0.01 N 164-167P 3 000(5)200/10(6) 163/189(6) 0.01/1(6) N, L 174.8-182p
16、 182-185P, 185-190p, 190-191.8P 17 000(5)200/10(6) 163/189(6)0.01/1(6) N, L 200-209P 9 000(5)3 194 1 L 226-231.5P 5 500 200/3(6) 160/194(6) 0.01/1(6) N, L 235-238p 3 000 3 194 1 L 250-252P 2 000 3 194 1 L 275-277 2 000(5)3 194 1 L 294-306 12 000(5)200/3(6) 160/194(6) 0.01/1(6) N, L 316-334 18 000(5
17、)200/3(6) 158/194(6) 0.01/1(6) N, L 342-349 7 000(5)200/3(6) 158/194(6) 0.01/1(6) N, L 363-365 2 000 3 194 1 L 371-389 18 000(5)200 158 0.01 N 416-434 18 000(5)200 157 0.01 N 442-444 2 000(5)200/3(6) 157/194(6)1 N, L 4 Rec. ITU-R RS.1029-2 TABLE 1 (end) Frequency band(s)(1)(GHz) Total bandwidth requ
18、ired (MHz) Reference bandwidth (MHz) Maximum interference level (dBW) Percentage of area or time permissible interference level may be exceeded(2)(%) Scan mode (N, L)(3)496-506 10 000(5)200/3(6) 156/194(6)0.01/1(6) N, L 546-568 22 000(5)200/3(6) 156/194(6)0.01/1(6) N, L 624-629 5 000(5)3 194 1 L 634
19、654 20 000(5)200/3(6) 156/194(6) 0.01/1(6) N, L 659-661 2 000 3 194 1 L 684-692 8 000(5)3 194 1 L 730-732 2 000(5)3 194 1 L 851-853 2 000 3 194 1 L 951-956 5 000(6)3 194 1 L (1)P: Primary allocation, shared only with passive services (No. 5.340 of the Radio Regulations); p: primary allocation, shar
20、ed with active services; s: secondary allocation. (2)For a 0.01% level, the measurement area is a square on the Earth of 2 000 000 km2, unless otherwise justified; for a 0.1% level, the measurement area is a square on the Earth of 10 000 000 km2unless otherwise justified; for a 1% level, the measure
21、ment time is 24 h, unless otherwise justified. (3)N: Nadir, Nadir scan modes concentrate on sounding or viewing the Earths surface at angles of nearly perpendicular incidence. The scan terminates at the surface or at various levels in the atmosphere according to the weighting functions. L: Limb, Lim
22、b scan modes view the atmosphere “on edge” and terminate in space rather than at the surface, and accordingly are weighted zero at the surface and maximum at the tangent point height. (4)First number for sharing conditions circa 2003; second number for scientific requirements that are technically achievable by sensors in next 5-10 years. (5)This bandwidth is occupied by multiple channels. (6)Second number for microwave Limb sounding applications. (7)This band is needed until 2018 to accommodate existing and planned sensors. Rec. ITU-R RS.1029-2 5
