Benefits of InSAR Based Earth Observation Monitoring
When it comes to persistent wide area monitoring, and in particular for difficult to access locations, space-based earth observation provides a wealth of advantages over traditional surveying methods for risk and stability mapping. Satellite based monitoring can overcome limitations of on-site surveying through wide area data coverage and efficient, accurate, repetitive, and cost-effective data collection, processing, and analysis.
Unlike optical satellite sensors that can only operate during daylight, Synthetic Aperture Radar (SAR) satellite systems provide their own energy source, allowing them to collect data day and night, and even “see” through clouds. Regularly acquired and freely available ESA Sentinel-1 SAR satellite data has become an appropriate and officially accepted data source, and Interferometric SAR (InSAR) based earth observation has matured to an established technological solution for persistent surface deformation monitoring from space.
SAR Interferometric Stacking techniques such as Persistent Scatterers (PS) and Small Baseline Subsets (SBAS, or Distributed Scatterers) can obtain very precise measurements of slow surface movements over long periods of time and have proven their reliability in monitoring surface deformation phenomena resulting from tectonic or human activities. Over the last decade, the vast amount of freely available ESA Sentinel-1 SAR satellite data, intensive development of InSAR processing techniques and increased computing capacity, have initiated the development of numerous InSAR monitoring services for all types of applications often covering entire countries and even the whole of Europe.