The Registration Algorithm Research Of Spaceborne InSAR Images

Interferometric Synthetic Aperture Radar(InSAR) is one rising technology to produce high resolution digital elevation nodel(DEM),to detect small earth motions,and so on. It has drawn extensive attention in variousfields such as topographic mapping,monitoring of earthquakes,volcanoes and glacier dynamics and other thematic mapping application.Registration of two or more images of the same scene is an important procedure in InSAR image processing that seeks to extract differential phase information not obtainable from each one of these images.Meanwhile,the accuracy of this step is crucial to the reliability of subsequent image processing and final results of the data processing chain,meeting subpixel precision request.How to acquire high precison homonymous points is more important for image registration. There are four parts in this paper.The paper mainly describe the process of image match.Firstly,the paper introduce the baisic pinciple of InSAR and the characteristic of the InSAR image briefly;Then it describe several methods of complex-image rigistatrion elaborately. The image registation is the most important part in the paper.It is desired to have the sub-pixel precision of registration between two complex-images for obtaining result of high precion. the paper take three steps to get the sub-pixel registration precision.First, it can obtain 30 pixels pricision of registration approximately using the parameters of satellite orbit.that is,it can get rough offset pixels between two complex-images;Then it has the pixel precision of registration using correlation registration method. It analyze 4 calculation methods of correlation registration through experiment result;max- spectrum image registraion is used to sub-pixel precison of registration on the selected pixel.Experiment result has proved the validity of the method.After image registration, interferogram can be obtained by mutiplying each pixelusing complex images.