Computation of Wind Vectors over the Ocean Using Spaceborne Synthetic Aperture Radar

he high resolution and large coverage of satellite synthetic aperture radar (SAR) offer a unique opportunity to derive mesoscale wind fields over the ocean surface and to investigate their spatial variation. For this purpose, different algorithms were developed and tested using SAR images from two European Remote Sensing satellites. In this article, the methods for deriving wind fields from SAR data are introduced. The wind directions are extracted from wind-induced streaks visible on most SAR images. Wind speeds are derived from the normalized radar cross section by applying an empirical C-band model. The different sources of error in wind retrieval that must be considered are discussed with respect to Radarsat/ScanSAR data. Furthermore, SARretrieved ocean surface winds are used to investigate the spatial variation of winds at different scales. (