Oil spill characterization with multi-polarization C- and X-band SAR

Single-polarization (VV or HH) C-band synthetic aperture radar (SAR) sensors have conventionally been utilized in remote sensing of marine oil pollution. This paper examines the capability of combining the complex VV and HH channels in C-band and X-band SAR for oil spill characterization and for discrimination between mineral oil spills and biogenic slicks. The two frequency bands are evaluated from a theoretical point of view and subsequently experimentally compared using a truly unique data set, consisting of quasi-simultaneous Radarsat-2 and TerraSAR-X data acquired during the June 2011 oil-on-water exercise in the North Sea. Multi-polarization features for the two frequencies are compared based on classification results. A potential for discriminating biogenic films from mineral oil slicks is found. The analysis shows that some slicks have internal zones that correlate well with expected thickness variations.