Abstract: A method and apparatus is provided, whereby a scanning, polarization and frequency diverse radar system measures the complete polarimetric characterization of weather targets without loss of scanning speed and without an additional ambiguity in the Doppler velocity beyond that given by Nyquist's sampling theorem. In one embodiment, a linear combination of a horizontally and a vertically polarized signal are transmitted at a predetermined first frequency. Cotemporaneously or nearly cotemporaneously with the transmitted signal of the first frequency, a horizontally polarized signal is transmitted at a predetermined second frequency. Horizontal and vertical receive channels receive echoes at the predetermined first frequency to determine, but not limited to determine, the co-polar elements of the scattering matrix. Horizontal and vertical receive channels receive echoes at the predetermined second frequency to determine, but not limited to determine, the cross-polar elements of the polarization matrix.