Complex InSAR radar image processing, GNSS, and TPS measurements to determine the Kaniv HPP dam deformations

Abstract

Abstract The article examines the combined use of satellite radar and stationary systems for monitoring spatial displacements of structures (SSMSDS) to detect vertical deformations of dams. The object of research is the dam of the Kaniv HPP in Ukraine. Dam deformation monitoring includes automated use of GEOMOS software, as well as a GNSS and TPS points network. DInSAR radar interferometry algorithms were applied to calculate the vertical displacements of the dam based on satellite observations. This study analyzed 30 satellite images from Sentinel-1, taken every 12 days from August 10th, 2020 to August 5th, 2021. The error in determining the vertical movement speed of the dam control points is based on the data of radio interferometric measurements relative to the results obtained from GNSS and linear-angular measurements for the period from August 2020 to February 2021. The error margin was found to be 0.41 mm/mo, with an average speed of -3.5 mm/mo during that period. From February 2021 to August 2021, the error margin increased to 0.85 mm/mo, with an average speed of + 1.7 mm/mo. Combining radar and ground measurements confirmed the seasonal spatiotemporal distribution of the rates of vertical dam displacements, with the dam body subsiding from August 2020 to February 2021 and then rising from February 2021 to August 2021. The radar measurements also identified anomalous speed zones with no GNSS points or reflectors for linear-angular measurements, which could indicate hidden defects related to the dam's strength. Overall, the results showed the effectiveness of using DInSAR technology and ground-based automated systems to monitor potentially dangerous objects, such as dams.