OCEAN FEATURE DETECTION USING MICROWAVE BACKSCATTER AND SUN GLINT OBSERVATIONS

Abstract

Synthetic Aperture Radar (SAR) satellite sensors have demonstrated their ability to observe ocean features related to dynamical processes including internal waves, currents, eddies, fronts, and the presence of bathymetric features. Because of the high resolution of available SAR sensors, circulation details and small-scale processes can be detected that are not observable by other sensors more frequently used for ocean research such as the NOAA AVHRR and the ORBVIEW2 SeaWiFS. In contrast to these, LANDSAT-TM thermal and optical channels can be used to observe sea surface temperatures, surface layer ocean color (upwelled radiance) as well as sun glint (reflected radiance) patterns of surface roughness at a spatial resolution comparable to that of SAR. Several examples of TM images obtained in 1997-2002 over the Argentine coastal ocean region where selected from an extensive data set. These images were analyzed and compared with a series of SAR images acquired over the same region by the ERS satellites and in some cases near coincident with the TM data. A close inspection of these data demonstrates that over a sun glint region, a high-resolution optical sensor can provide observations of sea surface patterns related to ocean dynamic processes very similar to those captured by SAR. The ability of TM to detect such ocean features can extend and complement the use of SAR data for ocean research