1. A dual-polarization radar system comprising: a dual polarization radar receiver; a processor coupled with the receiver; memory configured to store information including raw data received from the receiver, data processed by the processor, and processing code executable by the processor, the processing code including: instructions to receive raw dual polarization data as a function of range from the dual polarization receiver; instructions to determine a differential propagation phase shift as a function of range from the raw dual polarization data; and instructions to estimate the complex specific differential phase from the differential propagation phase shift by estimating the derivative of the differential phase shift data with respect to range in the complex domain.