Polsar Analysis of Coherent and Diffuse Double-Bounce Scattering Occuring Within a Vegetated Medium

This paper studies ground/volume and ground/trunk double-bounce scattering mechanisms occurring within a vegetated medium. Polarimetric Synthetic Aperture Radar data, acquired over different reduced-scale scenes, are used to isolate scattering mechanisms and evaluate their polarimetric features. It is found that ground/volume double-bounce is diffuse and strongly affects the retrieved ground patterns, with ground-projected contributions occupying a wide polarimetric space, which cannot be filtered out using polarimetric diversity. Whereas, the ground/trunk double-bounce is coherent, spatially well localized and can be easily filtered out. It is therefore shown that the assumption of ground response with a null HV polarization even for a smooth ground is not valid when a volume lies above it.