Reflection Symmetry for Polarimetric Observation of Man-Made Metallic Targets at Sea

In this paper, a new paradigm for coherent microwave polarimetric remote sensing observation of man-made metallic targets at sea is presented and demonstrated over real polarimetric synthetic aperture radar (SAR) data. It is based on the different symmetry properties of the sea and of the man-made targets. The rationale relies on physical principles instead of standard image processing. Hence, a simple and very effective filter to observe man-made metallic targets at sea by full-resolution dual-polarized SAR data is developed. The technique is compared to a classic polarimetric approach, namely the polarimetric cross-entropy (PCE) constant false alarm rate (CFAR), and it is shown to perform best. Experiments, undertaken over a large data set of single look complex (SLC) L-band ALOS-PALSAR and C-band RADARSAT-2 full-polarimetric SAR data, demonstrate the physical soundness of the theory and the effectiveness of the approach from an operational viewpoint.