Low-Backscatter Ocean Features in Synthetic Aperture Radar Imagery

Many ocean surface signatures in synthetic aperture radar (SAR) imagery are characterized by relatively low normalized radar cross section values. Distinguishing among these signatures objectively can be very difficult, especially with only the single-band and single-polarization SAR imagery available from the European Remote Sensing satellites and the Canadian Radarsat-1. Nevertheless, distinctive patterns, when interpreted in the context of the geographic region, season, and local weather conditions, can be extremely useful in properly identifying many of the observed low-backscatter features. Examples of such features presented here are interpreted based on the regional and temporal context of the SAR imagery as well as the morphology and temporal persistence of the features.