Application of Time-series InSAR Technology for Displacement Monitoring of the Srinakarin Dam

Abstract

Satellite data from Synthetic Aperture Radar (SAR) has successfully been applied to monitor dam displacement. Monitoring the dam's displacement is modern and accurate, but several factors can cause the dam's movement. Therefore, it should be inspected in a wide area and can be inspected at any time without restrictions on human resources in the field. This research applies timeseries InSAR technology to monitor the displacement of dam structures and to study a 3D rendering model suitable for engineering structural analysis through the Cesium the Platform for 3D Geospatial. We process the time-series InSAR using 24 Sentinel-1 images from October 18, 2017, to August 22, 2021. The study area is the Srinakarin Dam, located in the Ban Chao Noen area, Tha Kradan Subdistrict, Si Sawat District, Kanchanaburi. Thailand's largest earth core dam is 140 meters high, 610 meters long, and 15 meters wide. Usually, it can store 17,745 million cubic meters of water. From research, the results were aligned with the satellite line of sight (LOS) with a displacement of approximately -05.22 mm/yr. to +07.04 mm/yr. The application of the InSAR time series to detect dam motion is to identify the area where the displacement occurred. It is just a safety warning showing which areas need more accurate inspections and on-site inspections to check dam safety. This research demonstrates the ability to apply Time-series InSAR technology. It presents the results obtained by tracking the dam's movement in three dimensions via the Cesium the Platform for 3D Geospatial.