Polarimetric phased array weather radar: Concepts for polarimetric calibration

The National Severe Storms Laboratory (NOAA-NSSL) and the Advanced Radar Research Center at the University of Oklahoma (OU-ARRC) are presently involved in the design, development and construction of a cylindrical polarimetric phased array radar (CPPAR) to demonstrate polarimetric capabilities for weather sensing within the Multi-function Phased Array Radar (MPAR) project. The bias in radar meteorological polarimetric variables is dependent on a number of parameters like cross-to-copolar gain ratio, integrated cross-polarization level, cross-to-copolar phase, copolar beam-width mismatch and beam pointing angle mismatch [1-2]. In the first part we present a preliminary system design for CPPAR, in the second part we present a procedure for polarimetric calibration using a target of opportunity, namely rain. Polarimetric calibration such as this one is extremely important for polarimetric phased arrays, since calibration needs be done on a beam by beam basis.