On the Vicarious Calibration Methodologies in DIMITRI: Application on Sentinel-2 and Landsat-8 Products and Comparison with In-Situ Measurements

In the frame of the Sentinel-2 Mission Performance Centre (MPC) activities, in order to assess the S2A/MSI data quality and to monitor its evolution, DIMITRI is used to perform the vicarious validation of the Level-1C products. DIMITRI consists on several vicarious calibration methodologies for EO optical sensors: Rayleigh scattering, Sun-Glint, PICS and sensor-to- sensor inter-calibration.The first results of S2A/MSI from both Rayleigh and PICS methodologies are consistent and show an excellent quality of the L1C products. The cross- mission Intercomparison with LANDSAT-8/OLI over PICS shows good agreement within the ±5% mission requirements. The Intercomparison with concomitant ground-based TOA-reflectance over the Railroad Valley site shows a good agreement with a relative difference of 5%-10%. The uncertainties over the estimated calibration coefficients overall the results are found to be less than 5% for most of the S2A/MSI spectral bands.