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

Laboratory measurements of the polarimetric radar parameters for large spherical and spheroidal water scatterers are performed at 30 GHz to investigate their dependence on the scatterer shape. Antenna beamwidth and polarisation state. The measurements are made under multiple scattering conditions. The measured linear and circular depolarisation ratios for the spherical scatterers agree well with the theoretically calculated ones. The cross-polar level of the circular polarisation due to the multiple scattering is very large compared with that of the linear polarisation. The measurements for the spheroidal scatterers show that the shape and orientation distributions significantly affect the cross-polar correlation coefficient