Weighted multi-resolution phase-unwrapping method

The proposed method for phase unwrapping is based on a global analysis of t he interferometrical phase. The underlying principle is that the interferog ram is partitioned such that the unwrapped-phase function on each element c an be locally modelled by the mean values of the phase difference between n eighbouring pixels in azimuth and range directions. Using this local inform ation and a least-squares algorithm (Gauss-Seidel relaxation), an approxima te model of the unwrapped phase is then generated and tested by calculating the "residue image" defined as the difference between the original interfe rogram and the model itself. If there are residual fringes, then the result must be iteratively refined applying the method to the residue image. The accuracy of the proposed estimation depends on the dimensions of the elemen ts and the dynamic content of the phase, i.e. on the "roughness" of the gro und surface.