Accuracy and Uncertainty of Sen2Cor Bottom-of-Atmosphere Product

The Sentinel‐2 mission is fully operating since June 2017 with a constellation of two polar orbiting satellite units. Both Sentinel‐2A and Sentinel‐2B are equipped with an optical imaging sensor MSI (Multi‐Spectral Instrument) which acquires high spatial resolution optical data products. The Sentinel‐2 mission serves for observation of land‐cover change and deriving biophysical variables related to agriculture and forestry, monitors coastal and inland waters and is useful for risk and disaster mapping. Atmospheric correction processor Sen2Cor was developed to remove the effect of the atmosphere from Sentinel‐2 data. Sen2Cor is designed for mono‐temporal processing of Sentinel‐2 L1C data products providing Level‐2A Bottom‐of‐Atmosphere (BOA) reflectance product together with Aerosol Optical Thickness (AOT),Water Vapor (WV) and Scene Classification (SCL) maps. Sen2Cor can be downloaded from ESA website for individual processing by the users. In parallel, Sen2Cor is used by ESA for systematic L2A‐processing of Sentinel‐2 acquisitions over Europe since June 2017. ESA is preparing an operational global L2A‐processing with the integration of Sen2Cor in Sentinel‐2 ground segment (PDGS). The presentation provides recent validation results for the BOA reflectance product focusing on vegetated areas. Accuracy represents the mean difference of BOA‐reflectance retrieval to a reference value and uncertainty gives the rms around the reference. BOA‐reflectance reference is computed from Sentinel‐2 L1C Top‐of‐Atmosphere products using a radiative transport model with AERONET aerosol data as an input.