Registration of synthetic aperture radar images using a multiresolution Radon transform

摘要

This paper describes a new algorithm for registration of synthetic aperture radar (SAR) images. The algorithm is based on cross-correlation in the Radon transform domain, chosen principally because of the prevalence of line-like features in SAR images. The distributed nature of such features, and their persistence in the image independently of "look angle", make Radon-domain correlation appropriate for the peculiar challenge of SAR image registration. Furthermore, 2D cross-correlation in Radon space may be efficiently implemented as 1D convolution followed by backprojection. To handle local variations caused by terrain elevations and errors in global parameters, we use a coarse-to-fine matching strategy based on a novel multiresolution Radon transform pyramid. This may be efficiently constructed from an initial fine partition of the image into disjoint tiles, using alternating grouping and decimation steps. The whole algorithm is linear in the number of such tiles. Test results demonstrate that the new algorithm performs comparably to pixel-similarity-based registration when the look angle is the same, and much better for pairs with different look angles.