Characterization and Evaluation of Hybrid Polarization Observation of Precipitation

Abstract

Transmitting an arbitrary state of polarization while receiving horizontal?vertical polarization states is termed the hybrid polarization mode of operation. A theoretical model is developed for hybrid mode dual-polarization measurements in terms of the covariance matrix under linear horizontal?vertical polarization basis. The cross polarization encountered introduces biases in the copolar parameters estimated in the hybrid mode. Such biases are investigated for different precipitation types and propagation effects resulting from hydrometeor orientation and antenna properties. Polarimetric data measured by the Colorado State University?University of Chicago?Illinois State Water Survey (CSU?CHILL) radar transmitting horizontal?vertical polarization states is alternately used to demonstrate the measurement accuracy that would be expected in different storm scenarios observed in the hybrid mode.