Abstract
In the frame of the ESA Scientific Exploitation of Operational Missions project, ACRI-ST is responsible for the development and the intercomparison of new algorithms to validate the Sentinel 2 L1C product radiometry, beyond the baseline algorithms used operationally in the frame of the S2 Mission Performance Centre.
In this context ACRI-ST is in charge of the definition and implementation of a validation approach based on the exploitation of deep convective cloud (DCC) observations. Due to their physical properties, DCCs appear from the remote sensing point of view to have bright tops and white behavior; they can be used as invariant targets to monitor the radiometric response degradation of reflective solar bands. The observation of such targets allows an interband radiometry validation in the VIS-NIR domain (MSI bands between 443 and 865 nm) from a reference band considered as correctly calibrated.
We first present the DCC data selection criteria appropriate for the radiometric validation of the Sentinel-2 MSI instrument. The validation methodology is then thoroughly described and justified. It is based on the simulation of DCC top-of-atmosphere reflectance using radiative transfer modeling and its comparison to the actual MSI measurements to assess systematic interband biases. Final results and uncertainties are computed through the statistical analysis of a large collection of individual observations with a view to provide consolidated interband radiometric gains for MSI. These show the very good radiometric performance of MSI with interband gains much lower than 2%.
Sentinel-2 L1C Radiometric Validation Using Deep Convective Clouds Observations
In the frame of the ESA Scientific Exploitation of Operational Missions project, ACRI-ST is responsible for the development and the intercomparison of new algorithms to validate the Sentinel 2 L1C product radiometry, beyond the baseline algorithms used operationally in the frame of the S2 Mission Performance Centre.
In this context ACRI-ST is in charge of the definition and implementation of a validation approach based on the exploitation of deep convective cloud (DCC) observations. Due to their physical properties, DCCs appear from the remote sensing point of view to have bright tops and white behavior; they can be used as invariant targets to monitor the radiometric response degradation of reflective solar bands. The observation of such targets allows an interband radiometry validation in the VIS-NIR domain (MSI bands between 443 and 865 nm) from a reference band considered as correctly calibrated.
We first present the DCC data selection criteria appropriate for the radiometric validation of the Sentinel-2 MSI instrument. The validation methodology is then thoroughly described and justified. It is based on the simulation of DCC top-of-atmosphere reflectance using radiative transfer modeling and its comparison to the actual MSI measurements to assess systematic interband biases. Final results and uncertainties are computed through the statistical analysis of a large collection of individual observations with a view to provide consolidated interband radiometric gains for MSI. These show the very good radiometric performance of MSI with interband gains much lower than 2%.