Registration of Interferometric Sar Images

Interferometric synthetic aperture radar (INSAR) presents a new way of performing topography mapping. Among the factors critical to the mapping accuracy is the registration of the complex SAR images from repeated orbits. This paper presents a new algorithm for registering interferometric SAR images. A new figure of merit, the average fluctuation function of the phase difference image, is proposed as a figure of merit to evaluate the fringe pattern quality. The process of adjusting the registration parameters according to the fringe pattern quality is optimized through a downhill simplex minimization algorithm. Results of applying the proposed algorithm to register two pairs of SEASAT SAR images with a short baseline (75 meters) and a long baseline (560 meters) respectively are shown. We find that the average fluctuation function is a very stable measure of fringe pattern quality allowing very accurate registration.