Improved PSInSAR Technique on Surface Displacement Detection

• Main Authors: Shu-Fen Kuo, 郭淑芬
• Other Authors: 徐百輝
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/rhf5v3

碩士 === 國立臺灣大學 === 土木工程學研究所 === 107 === According to the investigation report issued by the Water Resources Agency, Ministry of Economic Affairs, there exists continuous subsidence in the Changhua and Yunlin areas of Taiwan. This adverse situation has greatly degraded the performance of local land utilization and the livelihood of inhabitants. In order to effectively address this issue, one must monitor the changes of ground surface elevation, and the solution nowadays is the Interferometric Synthetic Aperture Radar （InSAR）technique which has the advantage of broad area coverage, high measurement accuracy, and all-weather operations. The Differential Interferometric Synthetic Aperture Radar （DInSAR） and Persistent Scatterers InSAR（PSInSAR） techniques take two or more SAR images collected from different times and viewing angles over the same geographical location into the interferometric processing where the phase differences and small changes between images are extracted to render the information on geographical changes. However, for areas where the density of stabilized radar wave scatterers is low, such as flat terrain or lush vegetation, due to few fixed structures, the DInSAR and PSInSAR techniques may not function satisfactorily. To alleviate this limitation, the present study improves the differential SAR interferometry where the SAR images are first processed using PSInSAR technique to determine Persistent scatterer candidates （PSC）and then the images are further processed using statistical analyses such as Kolmogorov-Smirnov test, Cramer-von Mises test, Anderson-Darling test and correlation coefficient to acquire Distributed scatterer candidates （DSC）. By processing these scatterer candidates, the present study establishes ground subsidence displacement and velocity for the Tuku Township of Yunlin County using Sentinel-1A SAR satellite images of European Space Agency from 2016 to 2017.