Improvement of Vegetation Parameter Retrieval from Polarimetric Sar Interferometry Using a Simple Polarimetric Scattering Model

This paper concerns vegetation parameter retrieval from polarimetric interferometric SAR (PolInSAR) data. A two–component polarimetric interferometric model, designed for geophysical parameter retrieval, is presented for volumetric media over ground. It is based on a scattering model based polarimetric decomposition and the random volume over ground (RVoG) PolInSAR inversion technique. For forest vegetation observed at L–band, this model accounts for the ground topography, canopy layer and total tree heights, wave attenuation in the canopy, tree morphology in the form of orientation distribution and effective shapes of the branches, surface scattering contribution, and double–bounce ground–trunk interactions. A parameter retrieval framework is developed for repeat–pass acquisitions which aims to estimate and to compensate temporal decorrelation. The parameter estimation performance is evaluated on real airborne L–band SAR data. The contributions of the ground and the vegetation are separated to permit further analysis of ground properties and canopy layer morphology.