Theia Surface Reflectance Scientific Expertise Centre (SEC) brings together teams from Cesbio, LSCE, CNRM and LOA that develop high-resolution surface reflectance time series at level 2A (cloud masks for atmospheric correction) and level 3A (monthly summaries of light pixels).

Sentinel-2 and Landsat-8 data are used.

The product resulting from the Surface reflectance SEC has a scale of 10 m to 20 m (Sentinel 2) to 30 m (Landsat 8). The area covered corresponds to 10 times the area of France, i.e. 5 million km² (Sentinel 2) and France and Overseas regions and collectivities (Landsat 8). The update frequencies go from five days (Sentinel 2) to 16 days (Landsat 8) and one month (level 3A).


  • Since July 2014 for Landsat 8 (level 2A)
  • Since October 2016 for Sentinel 2 (level 2A)
  • Since October 2016 for Sentinel 2 (level 2A)


Olivier Hagolle