A statistical technique for phase unwrapping: application to InSAR data

The purpose of the paper is to investigate the possibility of reconstructing high slope and discontinuous terrain height profiles, starting from more than one wrapped interferometric phase signals obtained at different working frequencies from interferometric SAR systems. We propose an unwrapping method, based on a maximum likelihood estimation technique, that approximates the unknown surface by means of local planes. Since it does not exploit at all the phase gradient, it assures the uniqueness of the solution, also in the case of piece-wise continuous elevation patterns with strong discontinuities.