Coherence Analysis of Small Baseline Subset Displacement Model Types in Deformation Monitoring

Abstract

In coastal cities around the globe, engineering projects for land reclamation are being implemented to accommodate the demands of rapid population growth and economic development. To provide the necessary transformation services, airports are constructed in a variety of reclaimed areas, including overly moist agricultural regions, oceans, seas, lakebeds, and riverbeds. Nevertheless, the process of land reclamation can give rise to subsidence phenomena, which may subsequently result in damage to the infrastructure and buildings. It is therefore imperative that deformation monitoring be conducted in reclaimed airports to prevent potential risks. In this context, the small baseline subset (SBAS) method, which is a multi-temporal interferometric synthetic aperture radar (MT-InSAR) approach, has been adopted in numerous studies and has subsequently become a valuable asset. Moreover, the utilization of the SBAS method facilitates the implementation of deformation time series analysis in the reclaimed airport areas. In this study, coherence analysis was conducted on two types of SBAS displacement models: linear and quad. The analysis was carried out by monitoring deformation in Hatay Airport with a dataset of Sentinel-1A single-look complex (SLC) SAR images, spanning the period between 2 December 2017 and 29 January 2023. Furthermore, atmospheric correction was conducted using the Generic Atmospheric Correction Online Service for InSAR (GACOS) data. In this context, both the average deformation velocity and the cumulative deformation were acquired in the satellite line-of-sight (LOS) direction. Additionally, the cumulative deformation in the vertical direction was obtained for the linear and quad SBAS displacement models, with values ranging from -142.71 mm to 60.11 mm and from -224.97 mm to 73.98 mm, respectively. Finally, the cumulative vertical deformation difference map of the linear and quad SBAS displacement models was generated, and a coherence analysis was conducted. © 2025 Elsevier B.V., All rights reserved.