Utilization of the radar polarimetric covariance matrix for polarization error and precipitation canting angle estimation

The 3×3 radar polarimetric covariance matrix provides a complete set of measurements from distributed particles. Via optimum polarization theory, radar system polarization errors and particle orientation distribution parameters can be estimated. While the theory of covariance matrices and associated optimum polarizations for random media have been known for some time, the application to retrieval of microphysical information of precipitation is much more recent. Well calibrated covariance matrices and in particular the calibration of the phases of the two co-to-cross covariance terms hhS_vh*> and vvS_hv*> is necessary before optimum polarization analysis.