Simultaneous Observations of Ocean Surface Winds and Waves by Geosat Radar Altimeter and Airborne Synthetic Aperture Radar During the 1988 Norwegian Continental Shelf Experiment

Quasi-simultaneous measurements of the ocean surface by the Canada Centre for Remote Sensing (CCRS) Convair-580 (CV-580) synthetic aperture radar (SAR) were acquired on March 20, 1988, along an ascending pass of the Geosat radar altimeter as part of the prelaunch ERS-1 Norwegian Continental Shelf Experiment (NORCSEX '88). Over a region where the SAR look direction is parallel to the wind vector, a relationship between the ocean scattering cross ections measured by the Geosat altimeter and the SAR is obtained. In the regions where the wind direction is changing, an estimate of the wind direction is derived from the differences measured between the altimeter and the SAR scattering cross ections. Wavelength and wave directions derived from the SAR wave spectra re in good agreement with the sea truth data obtained with the wave directional buoys and with the altimeter-derived swell estimates. Significant wave height measured by the Geosat altimeter is compared with the buoy measurements and is used to assess the validity of the significant wave height deduced from the SAR.