1. Up link rain attenuation (dB) Rain fall results in attenuation of radio waves by scattering , and by absorption , of energy from the wave. Rain attenuation increases with increasing frequency and in worse at Ku band compared to C band. Studies have shown that the rain attenuation for horizontal polarization is considerably greater than for vertical polarization.
2. Satellite G/T (dB/k)
G/T ratio indicates figure of merit. G/T ratio is the ratio of gain of the satellite to the thermal noise temperature of the satellite. G/T ratio depends on the satellite components.
3. Uplink C/No(dB Hz)
The up link of a satellite circuit is the link in which the earth station is transmitting the signal and the satellite is receiving it .
Carrier to noise ratio of up link is given as
[C/No]U = [EIRP]U + [G/T]U - [losses]U + 228.6
=Transmitter EIRP- (Up link path losses + Up link rain attenuation) + Satellite G/T + 228.6 (dB).......
Example : calculate power rating of ground transmitter operating at following conditions Transmitter EIRP37.97 dB W, Up link rain attenuation-0.0 dB, Up link path loss 199.62 dB, satellite G/T(dB/K)-5.00