1、 Rec. ITU-R RS.1028-2 1 RECOMMENDATION ITU-R RS.1028-2*,*Performance 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 v
2、apour), 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 are a necessary prerequisite to the establishment of interference and sharing criteria; d) that surface brightness tempera
3、ture, the atmospheric temperature at points along a path and absorption coefficients can be determined from measurements of the sensor antenna tempera-ture, TA; e) that the surface brightness temperature and the absorption coefficients, in turn, depend upon the physical properties of the surface or
4、atmosphere that are to be sensed; f) that studies have established measurement sensitivity requirements; g) that studies have established that measurements in absorption bands are extremely vulnerable to interference because, in general, there is no possibility to detect and to reject data that are
5、contaminated by interference and because propagation of undetected contaminated data into numerical weather prediction (NWP) models may have a destructive impact on the reliability/ quality of weather forecasting; h) that passive microwave remote sensing is performed in absorption bands to obtain im
6、portant three-dimensional atmospheric data that are used in particular to initialize NWP models; j) that performance requirements for passive sensors can be stated in terms of measurement sensitivity, Te, and availability, measured at the satellite, assuming that degradation from other elements in t
7、he system will be small; k) that three-dimensional measurements of atmospheric temperature 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
8、, 50.2-50.4 GHz and 86-92 GHz, *This Recommendation, particularly footnote(4)to Table 1, should be brought to the attention of Radiocommunication Study Groups 1, 4, 6, 8 and 9. *Radiocommunication Study Group 7 made editorial amendments to this Recommendation. 2 Rec. ITU-R RS.1028-2 recommends 1 tha
9、t the measurement sensitivities suitable for passive remote sensing of the Earths land, oceans and atmosphere are as indicated in Table 1; 2 that in bands used for passive remote sensing, the required minimum availability of passive sensor data for each band shall be as specified in column 4 (Data a
10、vailability) of Table 1. TABLE 1 Performance criteria for passive remote sensing of environmental data Frequency band(s)(1)(GHz) Total BW required (MHz) Required Te(K) Data availability(2)(%) Scan mode (N, L)(3)1.37-1.4s, 1.4-1.427P 100 0.05 99.9 N 2.64-2.655s, 2.655-2.69s, 2.69-2.7P 45 0.1 99.9 N 4
11、.2-4.4s, 4.95-4.99s 200 0.3/0.05(4) 99.9 N 6.425-7.25 200 0.3/0.05(4) 99.9 N 10.6-10.68p, 10.68-10.7P 100 1.0/0.1(4) 99.9 N 15.2-15.35s, 15.35-15.4P 200 0.1 99.9 N 18.6-18.8p 200 1.0/0.1(4) 95/99.9(4) N 21.2-21.4p 200 0.2/0.05(4)99/99.9(4)N 22.21-22.5p 300 0.4/0.05(4)99/99.9(4)N 23.6-24P 400 0.05 99
12、.99 N 31.3-31.5P, 31.5-31.8p 500 0.2/0.05(4) 99.99 N 36-37p 1 000 1.0/0.1(4) 99.9 N 50.2-50.4P 200 0.05 99.99 N 52.6-54.25P, 54.25-59.3p 6 700(5)0.3/0.05(4) 99.99 N 86-92P 6 000 0.05 99.99 N 100-102P 2 000 0.005 99 L 109.5-111.8P 2 000 0.005 99 L 114.25-116.P 1 750 0.005 99 L Rec. ITU-R RS.1028-2 3
13、TABLE 1 (continued) Frequency band(s)(1)(GHz) Total BW required (MHz) Required Te(K) Data availability(2)(%) Scan mode (N, L)(3)115.25-116P, 116.0-122.25p 7 000(5)0.05/0.005(6) 99.99/99(6) N, L 148.5-151.5P 3 000 0.1/0.005(6) 99.99/99(6) N, L 155.5-158.5(7)p 3 000 0.1 99.99 N 164-167P 3 000(5)0.1/0.
14、005(6) 99.99/99(6) N, L 174.8-182p, 182-185P, 185-190p, 190-191.8P 17 000(5)0.1/0.005(6) 99.99/99(6) N, L 200-209P 9 000(5)0.005 99 L 226-231.5P 5 500 0.2/0.005(6) 99.99/99(6) N, L 235-238p 3 000 0.005 99 L 250-252P 2 000 0.005 99 L 275-277 2 000(5)0.005 99 L 294-306 12 000(5)0.2/0.005(6) 99.99/99(6
15、) N, L 316-334 18 000(5)0.3/0.005(6) 99.99/99(6) N, L 342-349 7 000(5)0.3/0.005(6) 99.99/99(6) N, L 363-365 2 000 0.005 99 L 371-389 18 000(5)0.3 99.99 N 416-434 18 000(5)0.4 99.99 N 442-444 2 000(5)0.4/0.005(6)99.99/99(6)N, L 496-506 10 000(5)0.5/0.005(6) 99.99/99(6) N, L 546-568 22 000(5)0.5/0.005
16、(6) 99.99/99(6) N, L 624-629 5 000(5)0.005 99 L 634-654 20 000(5)0.5/0.005(6) 99.99/99(6) N, L 659-661 2 000 0.005 99 L 684-692 8 000(5)0.005 99 L 4 Rec. ITU-R RS.1028-2 TABLE 1 (end) Frequency band(s)(1)(GHz) Total BW required (MHz) Required Te(K) Data availability(2)(%) Scan mode (N, L)(3)730-732
17、2 000(5)0.005 99 L 851-853 2 000 0.005 99 L 951-956 5 000(5)0.005 99 L (1)P: Primary allocation, shared only with passive services (No. 5.340 of the Radio Regulations); p: primary allocation, shared with active services; s: secondary allocation. (2) Data availability is the percentage of area or tim
18、e for which accurate data is available for a specified sensor measurement area or sensor measurement time. For a 99.99% data availability, the measurement area is a square on the Earth of 2 000 000 km2, unless otherwise justified; for a 99.9% data availability, the measurement area is a square on th
19、e Earth of 10 000 000 km2unless otherwise justified; for a 99% data availability the measurement 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 surf
20、ace or at various levels in the atmosphere according to the weighting functions. L: Limb, Limb 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 sh
21、aring conditions circa 2003; second number for scientific requirements that are technically achievable by sensors in the 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.
