Sensitivity of Calibration Parameters for Polarimetric Phased Array Weather Radar

A Polarimetric Planar Phased Array Radar called Advanced Technology Demonstrator is under construction at the National Severe Storms Laboratory, in Norman OK. The Planar Array antenna consists of 4864 dual polarization patch radiators. We investigate ways to calibrate this radar so that polarimetric variables can be obtained with acceptable bias. In general 9 parameters are needed to construct a set of linear equations relating second order moments of the received signals (at Ports 1, and 2 corresponding to intended H and V polarizations) to the pertinent elements of the polarimetric covariance matrix. Depending on the orientation of the array and the beam pointing direction the number of parameters and complexity of equations change. We study the sensitivity of the polarimetric variables to the various calibration parameters. We also suggest how to obtain or verify some of the calibration parameters by use of the Computational Electro Magnetic solver.