Assessment of the ASAR and PALSAR Sensors Applicability for Detecting and Monitoring of Landslides in the Zagros Area (Iran) Through Differential Synthetic Aperture Radar Interferometry (DInSAR)

Abstract

Lunching satellites equipped with the Synthetic Aperture Radar (SAR) sensor for interferometry applications has created a great chance to detect and monitor extremely slow, slow and even quick ground deformations. Accordingly, the objective of this research is to compare and assess capabilities of the ASAR and PALSAR sensors to detect, monitor and map landslides in part of the Zagros mountain range occurring in the south of Isfahan, Iran. In addition, generating an accurate landslide distribution map of the study area by combined usage of the ASAR and PALSAR images in two different passes was evaluated. Two image datasets including 17 PALSAR and 21 ASAR images acquired by the ALOS and ENVISAT satellites, respectively were processed by the Differential Synthetic Aperture Radar Interferometry (DInSAR) method. 16 interferogram pair images of the sensors were found to be suitable for the analysis based on an initial processing. 914 landslides were identified covering an area of 13,578 ha by processing the radar images and field studies as well. The maximum vertical displacement was estimated to be 1.58 m during 6 May 2010 to 2 September 2011 by analysis of both the PALSAR and ASAR pair images. The PALSAR images performed more efficient than ASAR images to map the landslides distribution due to the higher wavelength and subsequently more wave penetration and also lower incoherency. However, the ASAR can distinguish the landslides in more details because of its lower wavelength. It was concluded that the DInSAR method is more favorable for identification of the landslides with smaller area and higher frequency. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.