Propagation Effects Handbook for Satellite Systems - DESCANSO ...

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El E2 . . . . . . . . . . 1 \ . ----.---— -.—- \ \ \ \ I I \ LIMITED-TIME ATTENUATION STATISTICS LONG-TERM I AITENUATION DISTRIBUTION i I I I I I R! ) 1 I 1 1 1 1 1 1 1 1 1 1 RAIN RATE J [ 1 1 1 II 1 1 1 1 1 1 1 1 RAIN ATTENUATION Figure 6.3-11. Construction of Cumulative Attenuation Statistics Using the Distribution Extension Technique 6-46
. B . . . 4. Repeat the process for several points and join them with a smooth curve. Distribution extension in this manner assumes that the values rain rate and attenuation renain the same as the measured values~ the average, for times of the year different than the measurement period. This is not necessarily so. The physical distribution of raindrops along the propagation path in a stratiform rain, for example, differs from the distribution in a mild convective storm. Both conditions could produce local rainfall at the same rate, but the attenuation produced could be quite different. Thus in regions where there is wide seasonal variation in how rain falls~ distribution extension should be used with caution. The reliability of the extended distribution depends on how “typical” of the whole year the rainfall was during the measurement period. If the shapes of the limited-time and the long-term distribution curves are similar, the limited-time sample is statistically significant and the distribution extension will be valid. 6.3.4.3 Frequency Scalinq. If frequency scaling of measured rain attenuation (Step 3 of Figure 6.3-10) is required~ the specific attenuation scaling technique is recommended. In this technique specific attenuation data is utilized to scale the attenuation A from frequency fl to frequency fz. Referring to the equation for rain attenuation in Step 7 of Figure 6.3-1, the result is where of on (6.3-17) A, = A1(fl)~ Az = A2(f2), kl = kl(fl), . . . , etc. (6.3-18) This is a fair estimate for small frequency ratios (e.g.r less than 1.5:1), and moderate rain rates~ but errors can be large otherwise. This is because the above equation implicity assumes that rainfall 6-47
Page 1 and 2: 1 6.1 INTRODUCTION 6.1.1 purpose CH
Page 3 and 4: ,s Table 6.1-1. Guide to Sample Cal
Page 5 and 6: I . . 6.1.4 Other Propagation Effec
Page 7 and 8: . . collisions at normal atmospheri
Page 9 and 10: D 1000 100 10 1 U.S. Standard Atmos
Page 11 and 12: Frequency (GHz) 10 15 20 30 40 80 1
Page 13 and 14: If PW is not available from local w
Page 15 and 16: . . The equivalent heights for oxyg
Page 17 and 18: m t TEMPERATURE rC) o 5 10 15 20 25
Page 19 and 20: 6.3 PREDICTION OF CUMULATIVE STATIS
Page 21 and 22: LSTATION LOCATION AND ELEVATION STE
Page 23 and 24: The models require the following in
Page 25 and 26: I z za E 100 g w ~ z z K 50 a) ALL
Page 27 and 28: B . . . t- I I I I I 1 11/1 - . . .
Page 29 and 30: .- . 9 s@EQ - If Z S D, compute the
Page 31 and 32: 1 0.02 0.05 0.2 0.5 4. Compute D: U
Page 33 and 34: I . ,. . ~ q 8 H v ~ 1.0 0.8 0.6 0.
Page 35 and 36: Step 6 Calculate the attenuation ex
Page 37 and 38: m I : STEP 1 SELECT CLIMATE ZONE FR
Page 39 and 40: 9 10.OOOO 1.0000 0,1ooo 0.0100 0.00
Page 41 and 42: 1 6.3.3 Estimates of Attenuation Gi
Page 43 and 44: ● We now proceed exactly as in th
Page 45: STEP 1 GIVEN: STATION PARAMETERS SA
Page 49 and 50: . . ● 100 10 1.0 .1 .01 . . RAIN
Page 51 and 52: not normally available~ but empiric
Page 53 and 54: ● The intensity-duration-frequenc
Page 55 and 56: - GIVEN: STATION PARAMETERS OPERATI
Page 57 and 58: m I s 70 2(J I 10 0 a) BY SEASONS
Page 59 and 60: .“ ● change in rain rater the r
Page 61 and 62: m To x o 6 x(n wux!- (5 zawwvxw x 1
Page 63 and 64: ● ✎ ✎ ✎ 10 1 0.1 0.01 0 . -
Page 65 and 66: ● ✎ ✎ ✎ appears to be gener
Page 67 and 68: 6.4.2.3 Statistics of Microwave Eff
Page 69 and 70: ● For each hour’s observations,
Page 71 and 72: Plots of noise temperature and atte
Page 73 and 74: .- I where Lf is the fog extent~ in
Page 75 and 76: than a minute and on spatial scales
Page 77 and 78: . . . 022 = angle-of-arrival varian
Page 79 and 80: B . . Figure 6.5-2 represents the a
Page 81 and 82: - . . , 1 I t , 3 , I 1 # 1 1 aJ 0a
Page 83 and 84: I . . -. % i ! ~ * 76.00 I h 60.00
Page 85 and 86: I where the constants are the same
Page 87 and 88: .U . . \ Table 6.5-1. Fading Data P
Page 89 and 90: o -5C \ A — . \ \ \ \ N- ● ●
Page 91 and 92: I 1 \ 0,, FADE DEPTHS I 1 l.d 0.1 1
Page 93 and 94: 9 m ELEVATION ANGLE [DEGREESI ELEVA
Page 95 and 96: Figure 6.5-12 is an example for thi
Page 97 and 98:
equal. The fade distributions resul
Page 99 and 100:
m . ANTENNA BEAMVVID~ (DEG) d o 0 w
Page 101 and 102:
. . 6.5.5.2.2 Spatial Diversity. Pa
Page 103 and 104:
fluctuation power at 1 Hz is on the
Page 105 and 106:
develops (Pruppacher and Pitter-197
Page 107 and 108:
.8 where: f = frequency, in GHz r =
Page 109 and 110:
B . k 11.7 26 \ QHz DATA, CTS A VPl
Page 111 and 112:
\ for the 11.7 GHz CTS beacon at 50
Page 113 and 114:
● these do not correlate well wit
Page 115 and 116:
. However the XPD dependence on ele
Page 117 and 118:
-. 50 40 30 20 10 0 . T(XPD < ABCIS
Page 119 and 120:
9 electrostatic fields discharge ra
Page 121 and 122:
, f w m I
Page 123 and 124:
. XPD 2 = XPD1 - 20 lo91~ f ~ 1 0.4
Page 125 and 126:
● 3.0 14 0.6 0.3 0,1 0.0s 0.03 0.
Page 127 and 128:
where, for example, for the frequen
Page 129 and 130:
L .- . ., not appear to be sufficie
Page 131 and 132:
D ‘1 may be considered to be rece
Page 133 and 134:
D - 0 m a 80 60 40 20 0 -20 \ — i
Page 135 and 136:
m I s 1 \\ I , t Frequency (GHz) Fi
Page 137 and 138:
-. Table 6.8-1. Cumulative Statisti
Page 139 and 140:
D - The propagation margin is then
Page 141 and 142:
1- * w -180 -190 -m -21 / ---+---4~
Page 143 and 144:
- . . 6.9 UPLINK NOISE IN SATELLITE
Page 145 and 146:
280 260 240 220 200 180 160 140 120
Page 147 and 148:
6.10 REFERENCES Ahmed, I.Y. and L.J
Page 149 and 150:
● International Telecommunication
Page 151 and 152:
Atmospheric Emission observations,
Page 153 and 154:
8.6 and 3.2 mm Radio Waves by Cloud
Page 155 and 156:
I Strickland, J.I. (1974), “Radar
Page 157:
D Wulfsberg, K.N. (1964), “Appare
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