Anisotropic Scattering Due to Rain at Radio-Relay Frequencies

L. T. Gusler and D. C. Hogg have estimated that interference coupling due to rain is a significant factor in coordinating the shared use of frequencies between satellite-communications and terrestrial microwave radio-relay systems. Their calculations are based on the assumption that rain scatters isotropically. Calculations given here, based on the exact anisotropic angular scattering functions, do not alter their conclusions. The exact scattering patterns at selected frequencies in the range 1.4 to 300 GHz for rains whose drop sizes obey the Laws-Parsons distribution are presented for the range of rain rates 1 to 150 mm/hr.