Research On The Target Location Of Space-borne Synthetic Aperture Radar Image

Space-borne Synthetic Aperture Radar, as a kind of active microwave remote sensor, has the advantages of wide imaging swath, all-whether and strong penetrability. So it is one of the important aspects in the modern radar. Space-borne SAR has played more and more important role in many aspects such as country mapping, crops estimation, disaster evaluation and resource discovery.To utilize SAR image products adequately and efficiently, we often need locate accurately an arbitrary pixel in the image. In the process of image post-processing, precise pixel location is needed to guarantee the accuracy of geometry correction and distill effective cartographic information. The capability of absolute pixel location will not only conduce to image registration, but also provide a way of remote sensing images registration and mosaic from different time, different bands and different sensors.After comparison of several location methods of remote sensing image, Range-Doppler (R-D) theory is proved to have advantages as the footstone of pixel location model of SAR image. After analyzing SAR imaging theory and geometry model formula, the R-D location formulas, especially relative nadir position location formulas are derived. The R-D theory is further presented in detail and the methods of parameters acquisition and optimization solution are also described.At last, the thesis presents the algorithmic flow of the R-D theory and algorithmic realization of location model. The experiment results show that the theory has good location accuracy. In the end, the analysis of error sources and the method of further improving location accuracy are given.