Ocean surface wind direction measurement by scanning polarimetric microwave radiometry

The retrieval of ocean surface wind vector from polarimetric microwave brightness temperature fields is posed as a nonlinear inversion of the geophysical model function (GMF) for emission using maximum likelihood (ML) estimation. Applying the maximum likelihood estimator results in a weighted least-squares minimization problem that is valid for multi-look, multi-frequency, multi-polarization microwave brightness temperature measurements. By coupling this result with an empirically derived GMF, wind direction retrieval is demonstrated using multi-band conically-scanned polarimetric microwave brightness imagery obtained using the Polarimetric Scanning Radiometer (PSR) during observations over the Labrador Sea in March 1997.