Satellite Radar Imagery for Detection and Monitoring of Geohazards

This paper presents three case studies that were part of a 1-year study that explores the feasibility of using commercially available satellite and other aerial imagery to monitor the right of way of railroads for effects and conditions that could potentially trigger landslides and other geohazards. Two satellite image processing techniques in the Interferometric Synthetic Aperture Radar (InSAR) family have been studied and employed, that is, the Differential Interferometric Synthetic Aperture Radar (DInSAR) and the Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR). All satellite images used in this work are in the public domain and the software is open source. Showcase studies have demonstrated that the current satellite technology makes it feasible to monitor the railway right of way for large- and small-scale deformations and changes in the ground moisture content in adequate resolution. The frequency of acquisition of satellite images is adequate for the long-term monitoring of the infrastructure. The satellite analysis results can be superimposed to visual imagery for ease of visual inspection and evaluation. Future work for the development of a monitoring system of the railway right of way needs to focus on verifying the accuracy of the techniques with in situ measurements through conventional means and quantifying the changes of the moisture content.