Scattering properties of Pruppacher‐and‐Pitter form raindrops and cross polarization due to rain: Calculations at 11, 13, 19.3, and 34.8 GHz

Forward‐scattering amplitudes of raindrops are computed at 11, 13, 19.3, and 34.8 GHz for a real raindrop shape given by Pruppacher and Pitter, assuming plane waves at normal incidence to the drop axis. Horizontal and vertical polarizations are considered in the incident field. These forward‐scattering amplitudes are then used to estimate cross polarization by rain. Cross‐polarization factors are calculated for two kinds of raindrop canting angle distributions: gaussian distributions and a photographically measured distribution. The results show that the scatter of the drop canting angles reduces the cross polarization considerably as compared with that for equioriented raindrops.