Propagation Effects Handbook for Satellite Systems - DESCANSO ...

Table 6.3-2. Rain Rates Exceeded for 0.01% of the Time
Climate ABCDEFG HJKLMNP
Rate 8 12 15 19 22 28 30 32 35 42 60 63 95 145
SteR 2 Determine the effective rain height, hr, from;
hr = 4.0
= 4.0 - 0.075 (
+- 361 +: j6~< 36°
(6.3-11)
where $is the latitude of the ground station, in degrees N or S.
W Calculate the slant path length? h~ horizontal Projection
LG, and reduction factor, rpr from:
For @ ~ 5°,
= (h r - hO)/sin (@) (6.3-12)
LG = L~ COS (@) (6.3-13)
rp (6.3-14)
1 + 0.~45LG
where @ is the elevation angle to the satellite~ in degrees~ and ho
is the height above mean sea level of the ground terminal location~
in km. (For elevation angles less then 5°~ see Section 306).
Step 4 Obtain the specific attenuation coefficients~ K anda, at the
frequency and polarization angle of interest from Table 6.3-3. For
frequencies not on the table, use logarithmic interpolation for K
and linear interpolation for a. For polarization tilt angles other
than linear horizontal or vertical, use the relationships on Figure
6.3-6, Step 4, to obtain K and a.
Step 5 Calculate the attenuation exceeded lar 0.01% of an average
year from;
Ao,o1 = K Ro.01~ LS r p (6.3-15)
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