Rain depolarization measurements on a satellite-earth propagation path at 4 GHz

The effect of rain depolarization has been calculated as a function of rain rate, path length, and frequency based upon Oguchi's calculations of differential phase shift and differential attenuation due to oblate raindrops. The experimental values generally agree with the theoretical predictions, but the latter tend to underestimate the effect. This underestimation is possibly due to some near-field effect plus the errors introduced by approximating the raindrops as ellipsoids, especially at high rain rates. Nevertheless, theoretical and experimental values of the level of depolarization due to rain generally differ by no more than 3dB.