MARINE OIL SLICK AND PLATFORM DETECTION BY COMPACT POLRIMETRIC SYNTHETIC APERTURE RADAR

Compact polarimetric (CP) synthetic aperture radar (SAR) is a potential tool for operationally monitoring oil slicks and oil platforms because its large-coverage swath and abundant polarimetric scattering information. In this study, we use Cband RADARSAT-2 quad-polarization (quad-pol) SAR data to simulate CP covariance matrix elements and then construct pseudo quad-pol scattering coefficients by utilizing two different CP reconstruction algorithms. We develop an unsupervised classification method to discriminate oil slicks and platforms from clean ocean waters, using the relative phase, a logical scalar threshold that separates odd and even scattering events. The relative phases are estimated with the reconstructed co-and crosspolarization backscatters, which are positive in clean ocean surfaces where odd scattering is dominant but are negative for oil platforms and oil slick-covered areas associated with even scattering.