An iterative method to improve phase unwrapping of noisy interferograms

Extraction of topographic Digital Elevation Model (DEM) by interferometric data requires the recovering of an interferometric phase absolute value from its principal value (measured). This is carried out by appropriate algorithms called phase unwrapping algorithms. The authors propose a phase unwrapping algorithm that estimates phase gradient by a multiresolution approach and computes the final interferometric phase by an iterative process. Several examples show that only a few iterative steps are enough to reach the maximum performance with respect to algorithms that compute absolute interferometric phase value directly from a gradient estimate