Ocean Wave measurements using synthetic aperture radar

Abstract

Operating in wave mode the ENVISAT satellite to be launched in 2001 will provide synthetic aperture radar (SAR) data on a global and continuous basis. ASAR (advanced SAR) wave mode data acquired every 100 km the track will have several advanced features compared to the SAR wave mode data so far provided by the ERS satellites. This study presents different state of the art techniques, which make use of these features in order to obtain measurements of ocean waves and wind fields on a global scale. To simulate ENVISAT data in the pre launch phase, ERS-2 SAR wave mode raw data provided by ESA were reprocessed to complex 10 by 5 km SAR scenes (imagettes) using the BSAR processor of the German Aerospace Center (DLR). The ENVISAT like imagettes aquired every 200 km along the track are basis for global measurement of ocean wave direction, waveheight and wavelength as well as wind speed and direction. The expected performance and the processing requirements for the ENVISAT wave mode is discussed.