This challenge was identified based on the needs of the Space and Security community.
One of their main interests is related to the detection of changes over man-made and natural structures on the Earth Surface. Earth Observation (EO) data, in particular from satellites like Sentinel, offer the possibility to monitor an Area Of Interest (AoI) continuously to detect changes of interest over a specific area. In this challenge, the AoI us related to the investigation of migration routes and migration hubs, so that stakeholders interested in such topic can verify the output maps to verify the highlighted features. European Union Satellite Centre are providing Sentinel-1 SAR images to deploy this challenge. In particular, SLC StripMap Sentinel-1 images offer the highest available spatial resolution (5 m) independently of illumination (day and night) and weather (cloudy or cloud-free sky) conditions. Data will be processed to create a Multi-temporal stack of the amplitude signal and the coherence between two images, allowing the detection of small phase variations of the return radar signal. These indicate a possible change of Earth surface characteristics, which can be an indicator of a specific activity (natural or human).
The use of SLC StripMap Sentinel-1 for this application has not yet been explored. Since first preliminary tests offered promising results, BETTER is seeking to deploy an innovative tool for the investigation of changes of interest for the Space and Security community.
Example of multi-Temporal coherence from Sentinel-1
image, where blue areas represents area with no changes.