Propagation Effects Handbook for Satellite Systems - DESCANSO ...

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PLANE WAVE I p-o) I I I t- { VARVINO IN AMPLITUDE 00NBTANT IN AN(3LE I TIME FLUCTUATION OF AMPLITUOE bk-L) I I&) /# - I rp) TIME / I - - FLUCTUATION ~ _ _ _ * I t= ~~~~ OF ANOLE \ \\ I 1 \ , w I VARYINO IN ANGLE 00NSTANT IN AMPLITUDE { / ~TRO...ERE I ‘URBULE” ~ Figure 6.5-1. Decomposition into Coherent and Incoherent Components . A plot of the variance measurement, S2, expressed in, dB, is shown In Figure 6.5-2 for four representative frequencies for a 4.6 m diameter aperture. SZ is plotted as a function of elevation angle and equivalent path length for a 6 km high region of turbulence. 6-78
B . . Figure 6.5-2 represents the average Sz as derived from the O.S.U. empirical constants. However, since both 021, and OZZ may be represented in closed form as a function of Czn (Tatarski-1961), instantaneous~ diurnal~ or seasonal values for Sz may be found from this model given an estimate of the appropriate Czn. 6.5.2.2.1 Applicability of the Model. The empirical constants which were found from observed data are applicable for the prediction of average turbulence-induced propagation effects in a temperate climate, during the warmer seasons of the year, and under non-precipitating clear-air conditions. It is necessary to derive local estimates of Czn for the model if these conditions are not the same. 6.5.2.2.2 Distribution of Amplitude Variance. It is known that peak-to-peak variations of 30 N-units in the refractive index are expected on a time scale of days and hours (Theobold-1978). Corresponding fluctuations in received signal amplitude variance expressed in dB would be expected to be about 20 dB peak-to-peak for a fluctuation of 30 N-units out of an average of 345. Figure 6.5-3 shows a representative case of average amplitude variance at 30 GHz for a 4.6 m diameter aperture as a function of elevation angle. Curves for plus or minus 10 dB variation in C2n about the average are shown for comparison. A more exact representation of the expected distribution of amplitude variance may be obtained given measured statistics of variance variability about the average. Figures 6.5-4a and b present probability distribution functions of variance differences for 2 and 30 GHz earth-space signals measured over a period of 26 days. The satellite was undergoing transition in elevation from 0.38° to 45° and the mean variance was removed as a function of elevation angle. The 90% confidence limits of 14.6 and 14.7 dB, respectively, are in good agreement with the statistics of expected refractive index variation. 6-79
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
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. . collisions at normal atmospheri
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D 1000 100 10 1 U.S. Standard Atmos
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Frequency (GHz) 10 15 20 30 40 80 1
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If PW is not available from local w
Page 15 and 16:
. . The equivalent heights for oxyg
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m t TEMPERATURE rC) o 5 10 15 20 25
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6.3 PREDICTION OF CUMULATIVE STATIS
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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 and 46: STEP 1 GIVEN: STATION PARAMETERS SA
Page 47 and 48: . B . . . 4. Repeat the process for
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: . . . 022 = angle-of-arrival varian
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
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L .- . ., not appear to be sufficie
Page 131 and 132:
D ‘1 may be considered to be rece
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D - 0 m a 80 60 40 20 0 -20 \ — i
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m I s 1 \\ I , t Frequency (GHz) Fi
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-. Table 6.8-1. Cumulative Statisti
Page 139 and 140:
D - The propagation margin is then
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1- * w -180 -190 -m -21 / ---+---4~
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- . . 6.9 UPLINK NOISE IN SATELLITE
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280 260 240 220 200 180 160 140 120
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6.10 REFERENCES Ahmed, I.Y. and L.J
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● International Telecommunication
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Atmospheric Emission observations,
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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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