Airborne measurements of the sea surface have been carried out with an imaging polarimetric 16-GHz radiometer system, aimed at determining the wind direction. The radiometer system features a high-speed digital correlator, and it measures all four parameters of the brightness temperature Stokes vector simultaneously. Preliminary experiments have confirmed the directional signatures of the sea brightness temperature as reported by other researchers and have led to development of improved instrumentation with the intention of determining the wind vector pixel by pixel in the radiometer imagery. ¿ 1998 American Geophysical Union