On The Role of Coherence Optimization in Polarimetric SAR Interferometry

The quality of an interferogram of two SAR images is measured by a concept called coherence. Coherence is inversely proportional to the interferogram phase variance. Since the interferogram phase is sensitive to the terrain topography, coherence maximization has a potential application in DEM generation. In this paper, the interferometric coherence optimization methods are reviewed. The problem of bias in the optimization methods is highlighted using a complex multivariate Gaussian distribution for a multilook POLInSAR data simulation. Full polarimetric Lband SIR-C data sets are used to prove that the optimized coherences, are better than the conventional hh coherence.