Theia Sentinel-2 Snow Cover

The Theia Sentinel-2 Snow Cover Level-2B dataset provides snow cover data from Sentinel-2 mission with a 5-day revisit and a spatial resolution of 20 m. The dataset is organized into the original Sentinel-2 UTM Tiling Grid. Each of these tiles covers an area of 110 km x 110 km. Theia Products are generated over selected tiles. For justified research needs, it is nevertheless possible to request additional regions, subject to production capacity.

Each product contains two raster files and a metadata file:

• LIS_S2-SNOW-FSC*.tif provides the fractional snow cover:
  • 0: No-snow
  • ]0-100]: Snow cover fraction in percent
  • 205: Cloud including cloud shadow
  • 255: No data (permanent water bodies are classified as nodata)

• LIS_S2-SNOW-FSC-QCFLAGS*.tif provides quality flags for more expert users:
  • bit 0: MAJA sun too low for an accurate slope correction
  • bit 1: MAJA sun tangent
  • bit 2: water mask
  • bit 3: tree cover density > 90%
  • bit 4: snow detected under thin clouds
  • bit 5: tree cover density undefined or unavailable
  • bit 6: FSC in shaded slope set to 100

• LIS_S2-SNOW-FSC_*.xml provides various metadata.
  
• The filename of the product indicates the acquisition time in UTC. For example LIS_S2-SNOW-FSC_T11UNT_20170704T185934_1-10_01.tif corresponds to 2017/07/04 18:59:34.

The dataset can be cited using the following DOI: https://doi.org/10.24400/329360/F7Q52MNK

The algorithm and the scientific evaluation of Theia Snow products are detailed in this article : Gascoin, S., Grizonnet, M., Bouchet, M., Salgues, G., and Hagolle, O.: Theia Snow collection: high-resolution operational snow cover maps from Sentinel-2 and Landsat-8 data, Earth Syst. Sci. Data, 11, 493–514, https://doi.org/10.5194/essd-11-493-2019, 2019. More information about this dataset can be found in the Theia website