SAR Interferometry For Surface Deformation Monitoring

Synthetic Aperture Radar Interferometric (InSAR) based on the phase information extracted from SAR can provide the three-dimension information of the earth's surface and monitor small changes of the earth surface. Comparing to the traditional remote sensing modes, InSAR possesses many outstanding merits including the capability to work in all-time and all weather, high spatial resolution and strong penetrability through the ground or vegetation etc. InSAR is not only a valuable complement to the traditional remote sensing and photogrammetry, but also one of the most potential technologies for 3D topographic mapping and earth deformation monitoring. Thus, InSAR play a very important role in monitoring small changes of the earth surface and has been the hotspot of radar remote sensing.There are many potential application areas for InSAR technology in China. For example, in the west of China, InSAR may be the only feasible means for 3D topography mapping and updating. In some other areas like the big reservoir, it is nearly impossible to detect the ground deformation by the traditional leveling method. Moreover, it is difficult to take continual monitoring in large areas even with the GPS. But the InSAR system will work better in all these cases. Further more, InSAR and D-InSAR will also be a much valuable means for working safety monitoring and control in mining wells.The emphasises are laid on the main processes of InSAR, such as speckle suppression and filtering , phase unwrapping, reconstruct DEM and detecting deformation of the earth in this paper. The data of ERS-1/2 and ENVISAT are used to test the contents that are studied and the result is good.This paper falls into the following parts:1. Basic method and processing of InSAR were described.And the basic relationfrom the geometry of SAR and the math formula were deduced.2. The model and forming principle of speckle were analyzed. Different algorithmsof filters were compared. Then the effectiveness of different filters was demonstrated by ERS SAR data. At last a better algorithm was given.3. The principle of phase unwrapping was analyzed in this part. Different unwrapping algorithms were compared and demonstrated by the phase data. The advantages and disadvantages of different phase unwrapping were given. Meanwhile the qualitative and quantificational appraise to the result of phaseunwrapping were also given.And A phase unwrapping software system has been implemented. So the automatization of phase unwrapping became much better.4. Applying the Synthetic Aperture Radar interferometric (InSAR) image to generate the Digital Elevation Model (DEM);analyzing the factors influencing DEM precision and using the external DEM to estimate the precision of InSAR-DEM.5. Using the latest ENVISAT SAR data and ERS-1/2 data the results of the earthquake deformation of Bam area and Taiwan were obtained by D-InSAR technology, which were consistent with those of the other geoscience institutes.