Mitigation of cross-polar interference in polarimetric weather radar

Polarimetry is a very valuable resource for weather radar due to its ability to characterize the signatures of the objects scattering the signals. Thus it provides the additional information required for hydrometeor classification as well as significantly improved rain rate estimates. In addition certain meteorological events such as tornadoes and lightning have very specific signatures in the polarimetric data fields. The polarimetric moments are only as valuable as they are error free, free from cross channel interference and hence the polarimetric data quality is limited by the ability of the system to mitigate the cross channel interference. There are two paradigms in resolving this issue, antenna hardware research and design and signal processing interference mitigation. The former can result in unique but very expensive hardware designs. Techniques in the latter can mitigate the cross-polar interference while allowing relaxation of the hardware specifications to within current antenna designs and, with system modifications, be implemented on current operational polarimetric weather radars. Such a signal processing technique is described and preliminary simulation results are presented.