GeObservatory is activated in major geohazard events (earthquakes, volcanic activity, landslides,etc.) and automatically produces a series of Sentinel-1 based co-event interferograms (DInSAR) to map the surface deformation associated with the event. It also produces pre-event interferograms to be used as a benchmark.
GeObservatory can be activated in two ways:
• Manual activation. An authorized user provides to the application a json file delineating the Area of Interest and registering the timestamp of the event.
• Automatic activation. GeObservatory connects to EMSC and is activated when a major earthquake occurs. Criteria for the activation of GeObservatory is the magnitude of the earthquake and its depth.
After the system is triggered, the application automatically scans different Copernicus hubs, including the Greek Collaborative Ground Segment,
to find the appropriate Sentinel-1 satellite data for interferometry.
The engine for creating the interferograms is sarscape commercial software, which processes all three Sentinel-1 subswaths.
The administrator is notified about the progress and the status of processing steps automatically by email or by consulting information tables of the service metadata database.
The application orchestrator
In the back-end of GeObservatory lays an application server which orchestrates the enter service. Its main components are:
• The “Products collection and Task scheduling service” written in python. This program initiates the request processing, finds and downloads the necessary satellite inputs and controls the output production tasks. A QGIS plugin has also been developed to manual trigger GeObservatory through a user interface.
• The Service Metadata Database (postgresql) that contains processing information, input and output metadata
• The ENVI SARscape module is the interferogram production engine. The “Products collection and Task scheduling service” execute commands from ENVI sarscape module using IDL scripts in order to create the interferograms
• The IDL scripts that execute the main interferogram tasks calling the sarscape commands.