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 activation

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.

Input data

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.

Interferometric processing

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.

Interferometric processing chain in geObservatory

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.

Technologies and Architecture of geObservatory

All Sentinel-1A and Sentinel 1-B used in this applications are collected and ingested through the Hellenic National Sentinel Data Mirror Site (HNSDMS), a web-based system designed to provide EO data users with Search-Cataloguing-Sorting and Dissemination capabilities for the Sentinel products.

HNSDMS is operated by the National Observatory of Athens (NOA), while the hosting infrastructure is the Greek Research and Technology Network, which is powered by GEANT e-infrastructure, for reliable and fast network links, and unconstrained access to computing, analysis and storage, applications.

The current version of HNSDMS comprises the 2nd generation of the Mirror Site built upon the legacy of the 1st operational prototype version developed under the current EU-ESA GMES / NOA agreement. HNSDMS runs a customized version of the Data Hub Software (DHuS), which provides a simple web interface to allow interactive data discovery and download, and a powerful Application Programming Interface (API) that allows users to access the data via computer programs and scripts thereby automating/integrating the download within their workflow.

The Sentinel Collaborative Ground Segment Initiative

The SENTINEL collaborative ground segment initiative of the European Space Agency is intended to allow complementary access to SENTINEL data and/or to specific data products or distribution channels. It is composed of elements funded by third parties (i.e. from outside the ESA/EU Copernicus programme) and provides the framework for international cooperation.

Liability disclaimer

GeObservatory is a beta version application which is supported by the BEYOND team on a best effort basis. The interferometric products are generated on a fully automatic approach, without an intervention of an expert. The team is not responsible for the use of these products by third parties.

GeObservatory has been conceived and developed by the Geohazards remote sensing team of BEYOND Center of Excellence.

geObservatory team

Ioannis Papoutsis

Alex Apostolakis

Haris Kontoes

Andreas El Saer

For any information concerning GeObservatory functionality, its processing engine, suggestions and feedback please contact Ioannis Papoutsis