Optimization of SAR interferogram by using coherence information

The authors tested the applicability of coherence information for optimizing SAR (synthetic aperture radar) interferogram. The purpose of the optimization in this study is to improve the smoothness of the topographic fringe in a SAR interferogram, which results in better fringe for unwrapping. Coherence information was computed as the complex correlation coefficient between two SAR complex data. To optimize the interferogram, the maximum coherence value was searched in 3×5 window around the initial registered position between two data and then the phase difference was obtained from the pixel pair that has the maximum coherence. This optimizing method was attempted for several SAR complex data pairs. The effect of the optimization was found in some pairs. It was found that the increase of the coherence clue to the optimization was one of the important factors for the improvement of the smoothness