Pol-K distribution applied to detect oil slick on RADARSAT-2 sea surface imagery

The polarization dependent and independent scattering contributions of the sea surface could be separated using complex scattering matrix better than using the NRCS (Normalized Radar Cross Section) [1]. By achieving this separation, a polarimetric generalized K distribution (Pol-K) motivated by ENL analysis had been established. It is different from traditional speckle models which consider only the direct radar measurements and ignore the different scattering information inside pixel areas. The principle of this statistical modelling is based on the physical generation of speckle for each scattering mechanisms, i.e., polarization dependent Bragg and independent Scalar contributions. K distribution is a special case of PolK when the phase parameter α = 0. For the separated scattering contributions, K distribution describes the ‘tail’ shape of their histograms, but overestimates the peak ‘height’. This disadvantage disables K distribution for oil slick detection using the separated scattering contributions. In this work, we test the capability of Pol-K distribution for oil slick detection on the RADARSAT-2 sea surface imagery, for which the peak ‘height’ is an important property.