Interpreting sea surface slicks on the basis of the normalized radar cross-section model using RADARSAT-2 copolarization dual-channel SAR images

摘要

A simple automatic multipolarization technique for discrimination of main types of thin oilfilms (of thickness less than the radio wave skin depth) from natural ones is proposed. It is based on a newmultipolarization parameter related to the ratio between the damping in the slick of specially normalizedresonant and nonresonant signals calculated using the normalized radar cross-section model proposed byKudryavtsev et al. (2003a). The technique is tested on RADARSAT-2 copolarization (VV/HH) synthetic apertureradar images of slicks of a priori known provenance (mineral oils, e.g., emulsion and crude oil, and plant oilserved to model a natural slick) released during annual oil-on-water exercises in the North Sea in 2011 and 2012.It has been shown that the suggested multipolarization parameter gives new capabilities in interpreting slicksvisible on synthetic aperture radar images while allowing discrimination between mineral oil and plant oil slicks.