Detection and quantification of movements by remote sensing (InSAR)in permafrost area.

• Main Author: Echelard, Thomas
• Other Authors: Pacte, Laboratoire de sciences sociales (PACTE), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Sciences Po Grenoble - Institut d'études politiques de Grenoble (IEPG)-Centre National de la Recherche Scientifique (CNRS), Université de Grenoble, Philippe Schoeneich, Michel Gay
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2014
• Subjects: Mountain permafrost; Rockglaciers; Remote sensing; InSAR; Movement; Creeping; Pergélisol de montagne; Glaciers rocheux; Télédétection; Interférométrie radar; Mouvement; Fluage; [SHS.GEO]Humanities and Social Sciences/Geography; permafrost; pergélisol
• Online Access: https://theses.hal.science/tel-01128087; https://theses.hal.science/tel-01128087/document; https://theses.hal.science/tel-01128087/file/ECHELARD_2014_archivage.pdf

Rockglaciers are one the visual expressions of mountain permafrost and have been the focus of numerous and various studies in the last two decades. Two main topics are studied by the scientific community: i) better understanding the movements of active rockglaciers and the phenomena that generate those movements; ii) assessing impact of global atmospheric change on these periglacial shapes. Here we propose to contribute to the first topic by using remote sensing method of displacement measurements already used in other countries for rockglaciers studies: Differential Interferometric Synthetic Aperture Radar (D-InSAR). D-InSAR is a method of measurement based on the phase difference between two radar images, which represent the same area but at different time intervals. The technique generates interferograms, maps of surface deformation in two-dimensions allowing for the detection and quantification (in centimeters) of variations in distance between the target and the radar between two different data acquisitions. Recent research has shown that the InSAR technique can be used to semi-quantify rockglacier deformation (under the assumption that certain conditions are respected with regard to generating and interpreting the interferograms). In the present thesis, ERS radar images (dating from 1991 to 1995) and TerraSAR-X data (dating from summer 2012) were obtained in courtesy of ESA (European Space Agency) and DLR (Deutschen Zentrums für Luft- und Raumfahrt, German Space Agency) with the aim of generating interferograms. We are interested by the detection of rockglacier movements. The ERS archives allowed us to work at French Alps scale with moderate resolution (25m in ground geometry) whereas TerraSAR-X data have better ground resolution (10m) but our analysis are more local (Haute Maurienne/Haute Tarentaise) due to the cost of the data and the time-consuming nature of the analyzes. With ERS, we selected all archives data and chose the more relevant of them. Finally 9 interferograms were generated. To analyse this ...