Propagation Effects Handbook for Satellite Systems - DESCANSO ...

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Experimental measurements of the fade durations at 6 GHz for fades Xrom O to 21 dB below the long term median are shown in Figure 6.5.9 (Strickland, et al-1977). These measurements were made at Eureka, Canada during the month of July 1974 when the moisture content (N-value) is above the yearly average, This data is probably typical of continental air mass data. The frequency and elevation angle scaling factors for this data are not thoroughly confirmed, but the Tatarski (1961) model appears to model experimental results (CCIR-1978~ Rpt 718). The variance aPPears to scale proportional to frequency according to the relation: variance = 42.25 ~ — 5’6 c~z(p) PW6 dp ol where p is the distance along the path. (6.5-4) The cumulative distribution for the rate of change of signal amplitude between 0.4 second samples was found to be identical for positive and negative-going signals (Strickland, et al-1977). The measured distribution is given in Figure 6.5-10, but again the frequency and elevation angle scaling factors are unknown. 6.5.3 Phase Variations Phase variations arise due to the variable delay as the wave passes through a medium with variable refractivity and also due to wavefront ripple introduced by the “lumpy” medium. The former is termed phase delay fluctuations, while the latter effect is called phase scintillations. 6.5.3.1 Estimation of Phase Delay Fluctuations on Earth-Space Paths. An expression for the rms phase aperture antenna of diameter dar fluctuation for a finite circular 0+=”(1-$)!’’=)22 nx;0-6 6-90 (6.5-5)
I 1 \ 0,, FADE DEPTHS I 1 l.d 0.1 1 to m PERCfNTAOE OF fAOE8 FOR WHICH OROINAIE ExCEEOEO Figure 6.5-9. Cumulative Distributions of Fade Durations at 6 GHz 1 o 1 1 1 Illltl t I I 1 11111 I 1 I I 1 1111 I 1 I 1 lIJJ O.l 1 10 1 001 PERCENTAGE OF TIME ORDINATE EXCEEOED Figure 6.5-10. Cumulative Distribution of Rate of Change of 6 GHz Signal 6-91 \ D
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1 6.1 INTRODUCTION 6.1.1 purpose CH
Page 3 and 4:
,s Table 6.1-1. Guide to Sample Cal
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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
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. . 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
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The models require the following in
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I z za E 100 g w ~ z z K 50 a) ALL
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B . . . t- I I I I I 1 11/1 - . . .
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.- . 9 s@EQ - If Z S D, compute the
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1 0.02 0.05 0.2 0.5 4. Compute D: U
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I . ,. . ~ q 8 H v ~ 1.0 0.8 0.6 0.
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Step 6 Calculate the attenuation ex
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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 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: o -5C \ A — . \ \ \ \ N- ● ●
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
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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
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I Strickland, J.I. (1974), “Radar
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D Wulfsberg, K.N. (1964), “Appare
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