Application of high resolution spotlight TerraSAR-X data to landslide monitoring

Abstract

This paper seeks to demonstrate that radar-based remote sensing techniques, especially those based on orbital sensors, can be as effective as the conventional geotechnical and discrete GPS measurement ones for the detection and monitoring of well suited landslides. Unfortunately, deformation can only be retrieved for those landslides presenting a good orientation with respect the satellite orbit. In addition, many of the high mountain landslides are vegetated areas that decorrelate faster at X-band. As in these scenarios the number of persistent scatterers can be low and, at the same time, the area of interest is usually small, the processing can be benefited of the usage of high-resolution data that will maximize the chances of detecting persistent scatters coming from both natural targets and man-made structures. The high resolution Spotlight mode of TerraSAR-X is thus the perfect choice as it offers a fine resolution. In addition, its 11 days of revisit time and X-band carrier allows the monitoring of small variations in the landslide trend and deal with its variable dynamics. The landslide of study is ‘El Forn de Canillo’ (Andorra) where the deformation results will be compared and validated with those obtained with the deployed UPC’s Ground-Based (GB-SAR) X-band sensor.