A method to estimate statistics of rain depolarization

This paper is concerned with depolarization caused by rain due to nonsphericity of drops and the distribution of their axes orientations. The drops are assumed to be oblate spheroids having canting angles distribution obtained by Saunders. Differential phase shift as well as differential attenuation is important in the calculation of depolarization and the values proposed by Oguchi and Hosoya are utilized. In the first part expression to calculate depolarization amount for a uniform precipitation rate are presented. But communication engineers are usually interested on statistical variations of depolarization amount, so the second part of this paper is concerned with statistical distribution of depolarization. The rain cell proposed by Misme and Fimbel is used to describe the rain model over a path. If the precipitation rate distribution is known in one point of the path, the depolarization distribution is obtained by assuming only one rain cell along the path where, for a long time observation, the precipitation rate distribution for all points is the same.