Areal InSAR Monitoring for Natural Hazards

Areal InSAR Monitoring for Natural Hazards is Fragile Srl's large-area ground-deformation mapping service, built on space-borne synthetic aperture radar interferometry (InSAR). It addresses deformation that is spatially extensive, such as land subsidence, or many phenomena acting at once, such as landslides across a river catchment, and is aimed at civil protection agencies and at operators of linear infrastructure such as pipelines, roads and railways, who can use the measured displacements as inputs to risk evaluation.

Fragile mainly delivers the service with RAINS (Rapid Areal InSAR Survey), its own approach based on single two-pass interferograms and interferogram stacks. It produces spatially near-continuous raster maps of mean line-of-sight velocity, including on vegetated and sparsely urbanised slopes where landslides often originate. Stacks map rates of roughly 40 to 500 mm/year, and the provider describes the values as semi-qualitative. Where rates are lower or buildings are present, its SBAS-based MT-SBA method adds sub-centimetre displacement time series at stable reflectors, delivered as shapefiles. The provider works with Copernicus Sentinel-1 C-band radar imagery, and customers can receive periodic updates at a frequency chosen for each project.

Named clients for the service include Regione Umbria and the Emilia-Romagna regional agency for territorial security and civil protection (detecting slope movements), INRETE Distribuzione Energia (a regional displacement database for its gas pipeline network) and Enel Green Power. For Umbria, a 2022 presentation by the University of Bologna, Fragile and the regional civil protection centre reported 1,120 Sentinel-1 interferograms (October 2019 to January 2021) over 8,456 km2 and 252 InSAR deformation signals identified. Fragile, a University of Bologna spin-off, states that large-area analyses are less precise than site-specific studies.