Deformation Monitoring of Large-Scale Rockfill Dam Applying Persistent Scatterer Interferometry (PSI) Using Sentinel-1 SAR Data

The Persistent Scatterer Interferometry (PSI) analysis accurately estimates the change over time of only the PS points on the ground surfaces using the time variation of the phase change of pixels with a small amount of noise called Persistent Scatter (PS).The riprap on the external surface of a rockfill dam is well reflected by radar, and since many PS points can be obtained over the entire external surface of the dam, the amount of external deformation can be grasped in a planar manner. In this paper, the PSI analysis was conducted for six large-scale rockfill dams of TEPCO Renewable Power using the SAR (Synthetic Aperture Radar) data from Sentinel-1 C-band, with 22 to 32 scenes of southbound and northbound trajectories in FY2020, respectively. The external displacement of the rockfill dams was measured using the SAR data. As a result of comparing the results of PSI analysis with the external deformations measured by surveying, it is concluded that the results of PSI analysis could be used to evaluate the deformation of the rockfill dam for maintenance management.