Propagation Effects Handbook for Satellite Systems - DESCANSO ...

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~ o 1.0 1 0.90 0.80 0.70 0.60 0.60 0.40 0.30 8 a8 o.2a Lu wu~ z oi= ● o b ● o w ~ .0 z Lu $ .0 w & .a .( J . . . . . 10 20 POINT RAIN RATE (mm/hr) 30 40 50 60 70 I 1 1 I I I 20 GHz, ATS.6, ROSMAN, NC O RAIN RATE DATA (6 MONTHS) /J ATTENUATION ESTIMATE FROM RAIN RATE STATISTICS o ATS-6 ATTENUATION DATA FROM DISTRIBUTION EXTENSION TECHNIQUE [See Para. 6.3.4.2) ~30 10 16 20 35 0 6 ATTENUATION (dB) AT 20 GHz Figure 6.3-9. :tenuation Statistics Estimate Based on Measu”red Rainfall Statistics 6-42 #
● We now proceed exactly as in the Global Model application example (Section 6.3.2.2)~ using these values of R p instead of those in Table 6.3-1 or Figure 6.3-3. The results of these calculations are shown in Figure 6.3-9, along with the measured attenuation statistics. This data is presented to demonstrate the technique. More accurate data, covering a longer periodl is presented in Chapter 5. 6.3.4 Attenuation Estimates Given Limited Rain Rate and Attenuation Statistics 6.3.4.1 Discussion and Procedures. The system designer will virtually never find attenuation statistics spanning a number of years for his desired location, operating frequency and elevation angle. But by applying distribution extension and scaling procedures to the limited statistics available, the designer my make useful estimates of the statistics for the situation at hand. Distribution extension allows one to take concurrent rain rate and attenuation measurements intermittently over a limited period of time, then convert the data into cumulative attenuation statistics covering the entire year. The conversion requires stable cumulative rain rate statistics for the site or a nearby weather station~ and measurements taken over a statistically significant fraction of the year. Distribution extension is required in practice because it is often costly to make continuous attenuation measurements over extended periods. Rather, data are taken only during rainy periods. Scaling is required to account for differences between the frequency and elevation angle applying to the available statistics, and those applying to the actual system under consideration. This scaling is based on empirical formulas which~ to the first order approximation depend only on the frequencies or the elevation angle and apply equally to all attenuation values. To a better approximation, however, the rain rate corresponding to the attenuation and other factors must be considered as well. 6-43
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: 1 6.3.3 Estimates of Attenuation Gi
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 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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