Since 2002, the satellite coverage of the small agricultural area located southwest of Toulouse is particularly rich. Indeed, since this area benefits from a high density of satellite images in high- and moderate- spatial and temporal resolution spectral ranges (HSRT, high-speed real-time), the CESBIO provides a documentation service for this area. This service, called OSR SO (Observatoire Spatial Régional Sud-Ouest = South Western Regional Space Observatory), provides data on the characteristics, functioning and evolution of the area. The study area historically corresponds to a SPOT area, which is approximately 2500 km2 wide (see illustration below).
In 2011, the OSR SO study area was extended to the Pyrenees mountains thanks to a new mountain weather station, remote sensing systems and measurement of snow coverage area and height.
Additionally, since the end of 2015 the SENTINEL satellite (HSRT) images cover the whole area every 2 to 5 days. This major advance in remote sensing allowed the further extension of the OSR SO study area and allowed the specific gathering of data for the CESBIO “chantier Sud-Ouest » project.
Thus, in 2020, the OSR SO study area was redefined to focus on 4 south western zones:
- The Adour upstream basin/Gave de Pau
- The Neste system Gascon rivers
- Garonne and Ariège alluvial valley
- The Pyrenees mountains
Theses 4 zones are subjected to studies of water supply, soil and vegetation types