ESTIMATES OF CURRENTS IN THE NEARSHORE OCEAN REGION USING INTERFEROMETRIC SYNTHETIC APERTURE RADAR

Microwave remote sensing of the ocean surface using Synthetic Aperture Radar (SAR) is of great interest due to its high resolution and the p otential of nearly instantaneous coverage of large areas. The experien ce accumulated in ocean imaging by SAR indicates that there are substa ntial difficulties in interpretation of the obtained images of ocean w ave systems. Ocean surface currents are almost impossible to obtain fr om SAR imagery. The present paper reports on measurements of ocean sur face currents based on imaging of the nearshore regions of the Montere y Bay using an interferometric SAR. The method is a modification of th e conventional SAR which employs two spatially separated antennas. Thi s modification allows one to construct an interferogram from the two c omplex images obtained by each antenna, which provides direct mapping of the observed surface velocities. The present results demonstrate th e advantages of this novel technique in studying nearshore ocean surfa ce dynamics. In particular, spatial distribution of the longshore curr ent velocity is presented.