Evaluation of Polarimetric Calibration of the Horus Radar using Weather Returns

Fully digital rotating planar polarimetric phased array radar (PAR) is one of the technologies being considered to replace the existing fleet of operational WSR-88D weather radars across the United States. This architecture benefits from both high temporal resolution, relatively low cost (compared to 4-faced PAR), and flexibility. Of importance is to achieve the improvement in update times needed for weather surveillance while maintaining or exceeding current operational polarimetric data quality. To this end, a methodology using the “birdbath” scanning (vertical pointing) technique is presented to evaluate po-larimetric calibration of the fully-digital Horus PAR. Preliminary results indicate that the embedded copolar element patterns for the horizontal (H) and vertical (V) polarizations can be estimated using the birdbath technique. Furthermore, using the birdbath estimated patterns, it may be feasible to derive corrections for antenna-induced biases in polarimetric measurements.