Prediction of the effects of rain on satellite communication systems

The major propagation effects for satellite communication systems operating above 4 GHz are caused by rain. With the possible exceptions of depolarization and multiple scattering at frequencies above 20 GHz, these effects may be calculated if the distribution of rain intensity is known in both time and space. The major effects-attenuation and interference-require information about path and volume averaged rain intensities. Current prediction models are not capable of adequately estimating the statistical distributions of path and volume averaged values. Radar observations could provide the required data. The best information currently available for modeling these distributions are statistical cell or storm models derived from radar observations.