Consistent validation of Copernicus Sentinel-2 and Sentinel-3 optical missions

The Copernicus program is a European initiative for the implementation of information services dealing with environment and security, mainly based on observation data received from Earth Observation (EO) satellites. In the frame of this program, ESA launched the Copernicus Sentinel-2 and Sentinel-3 optical imaging satellites. These satellites deliver a new generation of optical data products designed to directly feed downstream services mainly related to land and ocean monitoring, emergency management and security. To ensure the highest quality of Earth Observation data from the Copernicus Sentinel-2 and Sentinel-3 optical missions, ESA set up the Optical Mission Performance Centre (OPT-MPC) supported by several Expert Support Laboratories (ESL). The OPT-MPC brings together the experience of the former separated S2 and S3 Mission Performance Centers. The main objective of the working group on atmospheric correction within OPT-MPC is to employ synergies across the missions on surface reflectance (SR), aerosol optical thickness (AOT) and water vapor (WV) validation. Harmonization of validation practices, approaches, metrics, terms and definitions will support inter-operability among missions. This can also result in a guideline for good validation practice for other optical remote sensing missions in the Copernicus program and worldwide. Eventually it will give recommendations for algorithm improvements. This presentation reports first results of this process and will show some examples for consistent validation of Copernicus Sentinel-2 and Sentinel-3 optical missions. It invites for discussion about validation methodologies and standards in the community