The Surveillance and On-demand Sentinel-1 SBAS Services on the Geohazards Exploitation Platforms

The Geohazards Exploitation Platform (GEP) is an ESA R&D activity of the EO ground segment to demonstrate the benefit of new technologies for large scale processing of EO data. GEP aims at providing on-demand processing services for specific user needs, as well as systematic processing services to address the need of the geohazards community for common information layers and, finally, to integrate newly developed processors for scientists and other expert users. In this context, a crucial role is played by the recently launched Sentinel-1 (S1) constellation that, with its global acquisition policy, has flooded the scientific community with a huge amount of data acquired over large part of the Earth on a regular basis (down to 6-days with both Sentinel-1A and 1B passes). The Sentinel-1 data, as part of the European Copernicus program, are openly and freely accessible, thus fostering their use for the development of automated and systematic tools for Earth surface monitoring. In particular, due to their specific SAR Interferometry (InSAR) design, Sentinel-1 satellites can be exploited to build up operational services for the easy and rapid generation of advanced InSAR products useful for risk management and natural hazard monitoring. In this work we present the activities carried out for the development, integration, and deployment of two SBAS Sentinel-1 services of CNR-IREA within the GEP framework, namely the Surveillance and On-demand services. The Surveillance service consists on the systematic and automatic processing of Sentinel-1 data over selected Areas of Interest (AoI) to generate updated surface displacement time series via the SBAS-InSAR algorithm. We built up a system that is automatically triggered by every new Sentinel-1 acquisition over the AoI, once it is available on the S1 catalogue. Then, the system processes the new acquisitions only, thus saving storage space and computing time. The processing, which relies on the Parallel version of the SBAS (P-SBAS) chain, allows us to effectively perform massive, systematic and automatic analysis of S1 SAR data. It is worth noting that the SBAS Sentinel-1 services on GEP represent the core of the EPOSAR service, which will deliver S1 displacement time series of Earth surface for the European Plate Observing System (EPOS) Research Infrastructure community.