Generalized-K (GK)-Based Observation of Metallic Objects at Sea in Full-Resolution Synthetic Aperture Radar (SAR) Data: A Multipolarization Study

An electromagnetic model, based on the generalized-K (GK) speckle distribution, has been developed to read the scattering features associated with metallic objects at sea in full resolution single-look complex (SLC) synthetic aperture radar (SAR) data. The sensitivity of the GK parameters is investigated in both copolarized and cross-polarized SAR data. It is shown that a proper combination of GK parameters exhibits a completely different behavior with respect to sea surface with and without metallic objects, when measured over cross-polarized SAR data. As a matter of fact, a simple and very effective approach to observe metallic objects in full resolution SLC cross-polarized SAR data, is proposed. Experiments undertaken over a large data set consisting of RADARSAT-2 SLC fine quad polarization SAR data, confirm model predictions, and show that the proposed approach is both physically-based and operationally effective, since it is able to provide a logical true and false output.