Method of Tie Points Extraction Based on Imaging and Coherent Information

For SAR images of two adjacent strips with the smaller overlapping area, the severe geometric distortion makes it difficult to extract directly the Tie Points (TPs). Based on imaging information and coherent information of the InSAR images, this paper puts forward a new method for extracting TPs. First, it makes the raw image process the affine transformation with the imaging information; and then it uses the feature matching method of optical image to obtain TPs; finally, the TPs are selected according to the quality map. Experiments on the real InSAR data (overlap region 15%) demonstrate that it can not only automatically extract TPs, but also the extracted TPs meet the requirements for the interferometric mapping of some scale. At the same time, it makes the number of strips reduce from five to three joining together for an image of some scale, which decrease greatly the mapping work and mapping cost.