Abstract: Phase unwrapping is not feasible for extremely large interferograms due to computation time and computer resources. Therefore, we propose a “divide-and-conquer” strategy: divide the whole interferogrm into some patches which are easy to deal with, unwrap each patch independently by using some classical phase unwrapping methods with the good congruence and smaller error propagation, piece all the patches unwrapped together by finding the solution to a minimum weighted continuity cost function and finally interpolate low-coherence areas. Experimental results, carried out on simulated and real data, show that the proposed approach is efficient for unwrapping extremely large interferograms and has not reduced much accuracy with respect to the processing as a whole.

Key words: minimum weighted discontinuity method, network-flow method, mosaic, phase unwrapping, interferometric SAR