Mitigation of cross-polar interference in polarimetric weather radar

Polarimetry is a valuable resource for weather radar due to its ability to characterize the signatures of the objects scattering the signals. As such, polarimetry provides the additional information required for hydrometeor classification as well as significantly improved rain rate estimates. Furthermore certain meteorological events such as tornadoes and lightning have very specific signatures in the polarimetric data fields. The quality and usefulness of the individual polarimetric moments are limited by the ability of the system to mitigate the cross channel interference that occurs when measuring these moments with separate channels. 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 relatively expensive hardware designs. Techniques that use signal processing 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.