Minimum Cost Flow phase unwrapping supported by multibaseline unwrapped gradient

Abstract:
The objective of the TanDEM-X Mission is the generation of a global high resolution Digital Elevation Model (DEM). To carry out this goal, two interferograms with different baselines will be acquired. We propose a novel two-stage multibaseline phase unwrapping method. Maximum Likelihood Estimation (MLE) is used to reduce the ambiguity and errors in gradient estimation on a pixel-by-pixel basis. Based on these estimates, Minimum Cost Flow (MCF) is used to unwrap the phase accounting for the overall conservative condition of the gradient. Hence the advantages of both techniques are efficiently integrated. Results on simlated data using TerraSAR-X parameters are reported.