Detecting Regional Ground Deformation By Differential Sar Interferometry Based On Permanent Scatterers

As a promising remote sensing technique, satellite synthetic aperture radar interferometry (InSAR) has been evolving remarkably in recent years. Its extended mode, i.e., differential InSAR (DInSAR), can be applied to detect large-area ground deformations with some prominent advantages like high accuracy and fine spatial resolution, which greatly complements some conventional ground- and point-based geodetic techniques such as GPS and leveling. This provides a viable and valuable space-geodetic approach for ground deformation detection and geophysical studies. However, the full operational capability of DInSAR has not been achieved until now due to two major negative factors. First, the spatio-temporal decorrelation may result in unacceptable noise in phase observations, particularly over slowly-deformed areas with dense vegetation coverage. Second, the atmospheric artifacts make deformation measurements contaminated.It is possible to mitigate the aforementioned negative impacts and to study the temporal behavior of deformations by tracking some natural and man-made objects, i.e., permanent scatterers (PS), with temporally coherent radar reflectivity, in the frame of time series of SAR images covering the same area (the technique is often termed PS DInSAR). Therefore, this thesis selects PS-based DInSAR as a research topic, and explores its key theoretical and practical issues to overcome decorrelation and atmospheric effects. The motivation of this research is to improve both accuracy and reliability in PS-based DInSAR and to offer a new approach for monitoring deformation-related hazards. The investigations performed in this thesis and relevant conclusions are outlined as follows.First, from both theoretical and practical viewpoint the thesis analyzes the influence of uncertainty in orbital data on accuracy of reference-surface phase, deformation measurement and reconstruction of digital elevation model (DEM). The testing results indicate the precise orbit state vectors provided by DEOS can meet the accuracy requirement of radar interferometry, while the coarse orbit state vectors...