Calibrated method for discriminating sea surface slicks using RADARSAT-2 co-polarized SAR images

A new polarimetric parameter based on the model for normalized radar cross section, containing resonant and nonresonant scatterings from the sea surface (Kudryavtsev et. al., 2003), is proposed for discrimination between mineral oil slicks vs. natural slicks. A possible efficiency of this parameter in operating applications was tested on four RADARSAT-2 co-polarization SAR images obtained for the annual oil-on-water exercises in the North Sea in 2011, 2012, and for the Oil Stones oil production site in the Caspian Sea, containing a priori known mineral oil (crude oil, emulsions), and plant oil (which modeled natural slick) slicks. The images span incidence angles from 30° to 38° degrees and the wind speed from 2 to 10 m/s. The parameter has shown to be almost independent on the incidence angle and wind speed for the tested data providing at the same time a desired discrimination between mineral oil and plant oil slicks.