Water and ice cloud discrimination by laser beam scattering.

Ice and liquid water phase clouds can be distinguished by the measurement of angular distribution of various polarization parameters at wavelengths for which there is a marked difference in the indices of refraction for the two phases. Mie single scattering theory calculations were made for a Deirmendjian cloud model Cl for wavelengths of 2.90 micro, 3.10 micro, 6.05 micro, 13 micro and 20 micro incident plane-polarized radiation. Plots of the angular distribution of the scattered radiation for the perpendicular polarization, parallel polarization, polarization ratio, polarization, ellipticity and plane of polarization of the polarization ellipse show marked differences in the scattering by ice and water clouds.