WindSat calibration and geophysical parameter estimation

Three aspects of WindSat performance are presented. (1). End-to-end system calibration is tested by comparisons between WindSat measurements and a robust model of the Earth TB using the vicarious cold reference method. (2). In an effort to determine probable causes for any calibration biases or scale errors that are identified, a refined Antenna Pattern Correction algorithm has been developed that includes main reflector aperture illumination and edge diffraction effects, in addition to the feed spillover effects that are already accounted for in WindSat's nominal flight processing algorithm. (3). A wind vector retrieval algorithm has been developed that is based on an empirical geophysical model function relating the four Stokes components of ocean surface emissivity to wind speed and direction. In order to implement an emissivity-based retrieval, decomposition of the radiative transfer equation is performed into surface and atmospheric contributions