A simple model for orbital diversity gain on Earth-space propagation paths

Simple formulas, appropriate for use by the system designer, have been generated to estimate orbital diversity gain on Earth-space propagation paths, as a function of satellite aperture angle, link frequency and elevation angles. The proposed relationships are based on a regression fitting analysis implemented on an analytical propagation model for calculating the outage probability of an orbital diversity protection scheme. The root mean square error of the simple model is less than 0.5 dB in all tested situations and over the entire range of angular separation, frequency and elevation angle. The resulting simple model is tested with experimental data taken from Japan. The agreement was found to be quite encouraging. Tabulated values for the 12 parameters are presented for some heavy rain climatic regions. The dependence on climatic zone is obvious.