Advanced Satellite Interferometry for Monitoring Road and Railway Infrastructure in Landslide-Prone Areas

Roads and railways are exposed to instability and damage in landslide-prone areas. While conventional ground-based techniques are too costly for regular, wide-area monitoring of unstable slopes and transpor-tation infrastructure, satellite multi-temporal interferometry (MTI) can now effectively assist in hazard assessment thanks to the improved temporal (days-weeks) and spatial resolutions (1-3 m) of the new satellite radar sensors. The most important strengths of MTI are i) wide-area coverage (up to tens of thou-sands km2) combined with high spatial resolution (meters) and precision of ground surface displacement measurements (mm-cm) and ii) regular, long-term (years) data acquisition with short revisit times (weeks to days) and the availability of long time series of data (since 1992). These strengths offer flexibility to MTI applications such as the possibility of using the same series of images for various scale hazard as-sessments (from regional to local). Importantly, engineering structure response to ground motion can be investigated at high spatial-temporal resolutions over large areas by using the new radar satellites (e.g., the Italian constellation COSMO-SkyMed; the German TerraSAR-X). To highlight the potential of MTI for monitoring transportation infrastructure stability in landslide-prone areas we present regional to local scale case study examples of MTI applications in Italy.