Polarimetric Bias Correction of Practical Planar Scanned Antennas for Meteorological Applications

This paper proposes two bias correction methods for the practical planar polarimetric phased array weather radar, namely, the boresight correction and the array pattern-based correction. As an extension of the projection matrix method developed in previous research, the performance of the boresight correction considering the measurement errors of element patterns and the impacts of entire array patterns on polarimetric variables is theoretically evaluated. It is shown that the measurement errors of element patterns are crucial for the polarimetric bias correction. Furthermore, for a planar electronically scanned antenna, the measurement performance of the linear depolarization ratio varies in the beam direction, while the measurement performance of the differential reflectivity remains almost the same within the beam scan area. In order to compensate the impacts of entire array patterns on polarimetric variables, the array pattern-based correction method is formulated, and its performance is theoretically analyzed. Assessments of the analysis and future research are discussed.