Characteristics of rain and ice depolarization for a 19- and 28-GHz propagation path from a Comstar satellite

Relationships between rain and ice attenuation and depolarization for several incident polarizations have been determined experimentally for the first time. The relationships are based on measurements made using 19- and 28-GHz beacon transmissions from a Comstar satellite. Vertical and horizontal incident polarizations experience much less depolarization on the average than circular polarization or linear polarization incident at45deg. The measurements confirm that the usual orientations of the major symmetry axes of nonspherical raindrops and ice crystals are nearly horizontal. Joint cumulative distributions of attenuation and depolarization for one year of continuous measurement at 19 and 28 GHz are also presented. These distributions are useful for determining joint attenuation and depolarization margins required to meet outage objectives of specific satellite communication systems. For example, the outage of a 19-GHz dual-polarized system received with a polarization angle21degfrom horizontal and having an attenuation margin of 20 dB would be depolarization-dominated unless the system could also tolerate at least -15-dB depolarization.