Error Analysis And Surface Deformation Application Of Time Series InSAR

As a new kind of space geodesy techniques, Interferometric Synthetic Aperture Radar (InSAR) which can make a high precision deformation monitoring and low cost for a large area, overcome the disadvantage of low spatial resolution and expensive for traditional geodetic methods, but it also has many limitations for itself, such as strict interference requirements and a large number of error sources (e.g. instrument noise, satellite orbit error, atmospheric delay, uncoherence, DEM error and so on) those factors greatly limited the application of this technology. Since the1990s, many researchers began to try some new models and methods to overcome the disadvantage of the traditional InSAR and produced a new technique of Time Series (TS) InSAR. TS InSAR mainly through analyzes a long time series of SAR data to reduce the influence of orbit, atmosphere, DEM error and low coherence in the interferometric phase. After nearly10years development, TS InSAR technique have huge development and produced some branches:Stacking, Persistent Scattering (PS) InSAR, Least Squares (LS) method, Small BAseline Subset algorithm (SBAS), Coherence Target/Coherence Point Target (CT) method and Temporal Coherence Point (TCP) InSAR. In the application of TS InSAR, although different function models were established for parameter estimated, because of the complexity and uncertainty for the error factors, stochastic model of TS InSAR technique developed slowly; at the same time due to the short development time of TS InSAR, how to combine the deformation observations of TS InSAR with the dynamic mechanism of physical inversion is still inadequate. Therefore, the Error Model and Surface Deformation Mechanism Application of TS InSAR are employed to study in this paper.In this paper, the recent10years of development of TS InSAR has carried on the systematic discussion, then compared the various branches of TS InSAR and summarizes the different characteristics of them. When applied the TS InSAR method, many factors such as the research aim, data quantity, and geological features should be considered, and my results provided a reference for scholars.Based on the error source for traditional InSAR and the function model for TS InSAR, the error source of TS InSAR was analyzed, and then the general mathematical model of TS InSAR was build up that perfect the mathematical theory of TS InSAR technique. After that, the simulated data were used to test the precision of parameters for equal-weight model and posterior-weight model for single master image and multi master image TS InSAR respectively. The test results show when the posterior-weight model was used to estimate parameter its precision did not have an obvious improvement than the equal-weight model, and which need more disk space and have lower efficiency, so now the equal-weight model was used in the TS InSAR technique for parameter estimated is reasonable.This paper used Multi-Temporal InSAR (MTI) technique to study the surface subsidence and underwater volume change of LangFang by two track ERS-ASAR datasets between2007.4and2010.9. Since1960s, the surface subsidence rate of LangFang increased gradually, although the sedimentation rate was controlled by the government in recent year, the speed up of urbanization inevitably leaded to large-scale groundwater extraction. Used the MTI technique, the high-precision velocity field from2007to2010obtained in this paper and the maximum rate of ground subsidence in LangFang is76.0mm/yr. Then assessed the results’precision and accuracy by used the two tracks’ result in the public covered areas and level point data respectively, obtain the velocity field within a precision of2mm/yr and an accuracy of3mm/yr. Based on the deformation results, this paper use free stress volume strain changes model to inverse the volume change of groundwater, the maximum peak volume change rate is1.15×10-4/yr, the total volume change of groundwater is-5.54billion m3/yr.This paper used a total of24scenes ALOS PALSAR satellite data between2006.10and2011.03to monitor the deformation for Changbai volcano area in recent years, and based on PSInSAR approach for data processing to obtain the time series and mean rate for deformation in the Changbai volcano regional. The results show that the magma activity for Changbai volcano is weak in recent years, only near the crater there is10mm/yr deformation rate. Based on the deformation results, this paper uses Mogi model to inverse the source parameters in volcanic area and the magma volume increased nearly1×106m3/yr.This paper used a total of40scene ASAR data between2004and2010to study the tectonic activity in Kashi Depression area. Based on InSAR TS+AEM time-series analysis model, the deformation rate of study area from2004to2010was-2mm/yr-2mm/yr, and the south flank of Atush fault divided the research area into1mm/yr uplift activity of Tianshan Orogenic Belt and1.5mm/yr subsidence activity of Kashi Depression. The results show convergence deformation with nonlinear characteristics of study area, and the deformation of the edge between Tianshan Orogenic Belt and Tarim Basin bigger than the inside Tianshan mountain. Based on the deformation results, this paper uses a dip-slip fault model to inverse and get south of the Atush fault with average dip angle of35°, fault slip rate of2.3-2.5mm/yr and average fault closure depth of10.5km, suggesting the SAP is a shallow dip-slip reverse fault, supporting the results of geological surveying.