Performance improvement of InSAR local co-registration method with multiresolution interferogram

In this paper, we propose an advanced co-registration method for Interferometric Synthetic Aperture Radar (InSAR). Previously, we proposed a sub-pixel scale coregistration method which employs the number of singular points (SPs) and the amplitude information as the evaluation criterion (SFS-SPEC method). To improve the accuracy of the co-registration, here we propose to create a reference interferogram which is generated with a large-number multilook. This reference interferogram is used in the evaluation process to avoid the phase noise of which effect is large in the small-number multilook interferogram. That is, we calculate the phase difference between the co-registered pixel value and the pixel value of the reference interferogram. We compare it with the shape-from-shading(SFS)-estimated gradient to see whether the co-registration result is proper. Experimental result shows that the proposed method improves the quality of the interferogram.