Activity Tracking and Evaluation of Large-scale Collapse Zones using Synthetic Aperture Radar Differential Interferenc

This study used synthetic aperture radar interference technology (InSAR) to monitor the activities of large-scale collapse zones in southern Taiwan (Tainan City, Kaohsiung City, Pingdong County). Large-scale collapse zones are widely distributed, in addition to the construction of observation instruments, how to use other telemetry technology to quickly obtain relevant change information as monitoring and early warning indicator is a vital issue. SAR images from southern Taiwan from 2015 to 2019 were analyzed to monitor the ground surface changes using synthetic aperture radar differential interference technology (DInSAR) and permanent scattering interferometry radar technology (PSInSAR), and were verified using global navigation satellite system measurements. DInSAR analysis shows that the vertical displacement of the surface is ±60mm, which is within the range of elevation tolerance error, so it is not possible to use the satellite tracking station to compare the trace displacement in large collapse areas. However, PsInSAR results show that if there is PS point in a large-scale collapse zone, the PS point may be used as index of stabilization, and once the PS point suddenly disappears, it is highly likely that the area will change, and special care should be taken.

Keywords: Interferometric SAR, large-scale collapse zones, PSInSAR