An inversion algorithm applied to SAR data to retrieve surface parameters

An inversion algorithm is used to retrieve surface parameters from airborne SAR data obtained over areas of low vegetation and bare soil fields. The algorithm is based on a nonlinear least-squares criterion, and allows the simultaneous inversion of all surface parameters through an iterative procedure. The algorithm is formulated in a manner to include the statistics of the unknown surface parameters and of radar measurements. The surface model can be chosen arbitrarily depending on each particular application and surface type. The authors have chosen a small perturbation model and described the surface in terms of its permittivity, rms surface height, and correlation length. The performance of the inversion algorithm is first evaluated by using synthetic data. The method is then applied to SAR data and the results are compared to ground-truth measurements where available