PS-InSAR TECHNIQUE FOR LANDSLIDE DEFORMATION IN THE THREE GORGES RESERVOIR AREA USING ENVISAT ASAR DATA STACKS

摘要

This technique is well-known for its applications in subsidence of landslide monitoring analysis. However, practical applications of D-InSAR are limited by major drawbacks such as geometric and temporal decorrelation, as well as atmospheric disturbances. With the PS-InSAR techniques, a long time series of SAR images is combined to identify point-like stable reflectors (PSs), which can overcome the problems for traditional D-InSAR technique so as to improve the accuracy and reliability of deformation measurements. However, its application in landslide deformation monitoring has just become a hot topic of research in recent years. Landslide monitoring in the Three Gorges areas with PS-InSAR techniques is difficult due to environmental conditions such as strong terrain relief, dense vegetation cover, and complicated atmospheric variation/ condition. Such problems may hinder the PS-InSAR analysis. InSAR is a powerful technique that exploits phase information of SAR images to measure ground surface movements. Landslide deformation and monitoring using D-InSAR technique with millimetre accuracy is an important application of satellite SAR data acquired in repeat-pass mode. To solve these such problems, B.M. Kampes, R.F. Hanssen and P. Marinkovic developed the DORIS to make use for SAR interferometric processing, DEM generation- creation of digital elevation model and using the created DEM obtaining an interferometric containing displacement information. Andy Hooper and David Bekaert developed the StaMPS to make use of spatial-temporal filtering to extract deformation components from time-series interferometric phase signal. In this study, I have used D-InSAR and PS-InSAR techniques for landslide movement detection and deformations and monitoring by time series data and analysis at the Three Gorges Reservoir area. With ENVISAT ASAR 09 images of multiple tracks acquired during the period 08th February 2004 to 12th June 2005 years were used as test data. Using PS-InSAR method, identified areas with high risks of slope failure at the Three Gorges area and detect time-series deformation at landslide bodies.