According to the definition used by the Working Group on Calibration and Validation (WGCV) of the international Committee on Earth Observation Satellites (CEOS), validation is the process of assessing, by independent means, the quality of the data products derived from the system outputs.

The S2RadVal (Sentinel-2 Radiometric Validation) project (2016 – 2018) aimed at developing and inter-comparing algorithms for validating the radiometry of Sentinel-2 Level-1 products. This two-year project pursued two main objectives:

• The development of four algorithms to validate the radiometry of Sentinel-2 products and the assessment of associated uncertainty budgets:
  • The first approach is based on the observation of Deep Convective Clouds (DCC method)
  • The second approach uses RADCALNET measurements
  • The third approach allows the validation of low/medium radiances
  • The last approach uses RADCALNET measurements and Sentinel-2 products for validating the radiometry of mid/low-resolution sensors such as Sentinel-3/OLCI.
• The organisation of an inter-comparison workshop with entities external to the consortium .