VtWeb

VtWeb is a free-access, client-server Earth observation platform developed by VisioTerra, a French Earth observation consultancy founded in 2004. Open to citizens, scientists and students at visioterra.org/VtWeb, it addresses the difficulty of finding and handling free satellite, weather and climate data that is scattered across the web and runs to petabytes: VisioTerra describes it as a Data Processing Relay that delivers only the information needed over the user's area of interest, even on a low-bandwidth connection.

From a web browser, users browse catalogues of free data including Sentinel-1 radar, Sentinel-2 optical, Sentinel-3 OLCI, SLSTR and SRAL, Sentinel-5P TROPOMI atmospheric products, Landsat, the CNES SPOT World Heritage archive of SPOT-1 to SPOT-5 images, ERS and Envisat heritage data, Copernicus Marine and ECMWF model outputs, elevation models and geological maps. Data are processed on the fly (colour composites, indices such as NDVI, filters, and orthorectification of Sentinel-1 scenes from the physical observation model), and users can write their own processing in VisioTerra's POF-ML macro-language. Views are shown on a 2D map or a 3D globe, with near-real-time and archive data, time-series and multi-sensor animations for analysing change.

Views can be shared as "hyperlooks" and exported as GeoTIFF or KML/KMZ, or streamed as WMTS into GIS projects. VtWeb runs on VisioTerra's own servers in Champs-sur-Marne, and VisioTerra uses it as the base for derived platforms such as ESA's Sentinel Vision and the CryoSat, GOCE and Swarm data viewers.