Some Research On Realizing Speckle Suppression And Evaluation For SAR Images

Synthetic Aperture Radar (SAR) is a kind of high resolution imaging radar, which has been developed since World War II. High-resolution radar image can be obtained under all weather, day-and-night and long distance conditions, so it is of high value in military and civil applications. Now research on image evaluation gradually becomes the hot topic of study. Supported by the Foundation Research Project of Jiangsu Province (The Natural Science Fund NO.BK2001047) "Research On Image Quantitative Evaluation of SAR", we discuss the statistical characters of SAR image, speckle suppression and SAR image evaluation etc.In the preface to this article, first, the basic purpose and significance of speckle smoothing and quantitative evaluation for SAR images are introduced briefly. Secondly, we look back on the history of the speckle reduction and image evaluation. And finally, the principal contribution of this dissertation is summarized here.In chapter 2 we particularly describe the mechanism of speckle forming, discuss the noise model and the statistical characteristic of SAR image.In chapter 3 traditional algorithms of suppressing speckle are discussed .The main parameters for evaluating the quality of image are introduced.In chapter 4 we research on Lee filter based on adaptive windowing, then propose an improved algorithm on forming window, and finally discuss experimental results.In chapter 5 Lee filter based on adaptive windowing is realized on multiprocessor SHARC, then experimental results and executive time are analyzed.In chapter 6 we research on a denoising technique through shrinking the wavelet coefficients adaptively, then fuzzy membership in Fuzzy Mathematics is introduced to put forward wavelet fuzzy SNR to evaluate quality of SAR images based on it. Experiment results and academic analyses show its efficiency.In the end, conclusions are made and the possible future work is explained.