Ship detection by using the M-Chi and M-Delta decompositions

Ocean surveillance is an important application in synthetic aperture radar (SAR) imagery. Polarimetric SAR (Pol-SAR) provides the multi-channel scattering information and hence is very promising for earth observation. Recently, the dual polarimetric SAR especially the hybrid dual-pol mode (i.e., compact polarimetry) has been given a growing concern. It can provide wide imaging swath coverage with reduced system complexity and thus is of great potential for maritime surveillance applications. Compact decomposition methods have been widely evaluated and applied to the land cover applications. In this study, we investigate the performances of compact decompositions for ship detection. The surveillance scenario is focused on the coastal areas, where low wind regions (LWR) and small ships with low backscattered intensity often appear in Pol-SAR imagery. The compact m-δ and m-χ decompositions are included to show the importance of the contribution of total backscattered energy in ship detection. Results are demonstrated on two RADARSAT-2 acquisitions over Tianjin port and Dalian port, China.