Sentinel-1 for monitoring tunnel excavations in Rennes, France

Abstract The present study comes in the context of tunnel excavation monitoring. To detect and explain the characteristics of ground displacements due to tunnel excavations, a PsInsar processing chain for Sentinel-1 images using S1TBX and StaMPS tools is set up. Then, it is applied to study surface displacements over the line b of Rennes city metro. This study exploits 20 Sentinel-1 images covering Rennes City, France, over a period of 2.5 years. Mean displacement velocity map and displacement time series show that the detected deformations are correlated in space and in time with the excavation works. Although we did not had the possibility to validate PsInsar results by ground truth data (levelling, GNSS), we demonstrate, through this blind experiment, that we can detect a dense PS cover, the feasibility of small displacement scale and rate monitoring using a small set of Sentinel -1 images. To improve these results, we forecast to use a bigger set of images and to compare the result to ground data.