Laboratory measurements of polarimetric radar signatures of randomly distributed spherical and spheroidal scatterers at 30GHz

Laboratory measurements of the polarimetric radar parameters for large sphe rical and spheroidal water scatterers are performed at 30GHz to investigate their dependence on the scatterer shape, antenna beamwidth and polarisatio n state. The measurements are made under multiple-scattering conditions. Th e measured linear and circular depolarisation ratios for the spherical scat terers agree well with the theoretically calculated ones. The cross-polar l evel of the circular polarisation due to the multiple scattering is very la rge compared with that of the linear polarisation. The measurements for the spheroidal scatterers show that the shape and orientation distributions si gnificantly affect the cross-polar correlation coefficient.