Principles for the radar determination of the polarization properties of precipitation

The principles for determining certain parameters of precipitation particles by means of a radar with two-channel orthogonal polarization capability are discussed. The parameters are or are related to the mean shape, mean orientation angle, the degree of randomness of the particle orientation, and also to particle size and phase state. The preferred orientation of such particles results in the medium being anisotropic. The propagation aspects of the problem are considered in terms of additional parameters which include the differential attenuation, the differential phase shift, and the tilt angle of the anisotropy axes. Formulas are derived for determining the parameters in terms of radar observables. A limited sample of results from 16.5 GHz data is presented in order to illustrate the radar determination of each parameter.

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