Sentinel-2 radiometry validation method based on DCC observations


 

Due to their physical properties, Deep Convective Clouds (DCC) appear from the remote sensing point of view, bright and  spectrally stable targets which can be used to monitor the radiometric response degradation of reflective solar bands (typically from B1 to B8a for Sentinel-2).

One radiometric validation method developed in the frame of the S2RadVal project is based on Deep Convective Cloud (DCC) observations: The TOA signal measured by the Sentinel-2/MSI sensor is compared to a theoretical signal simulated in the same conditions (geometries, atmosphere, etc.). The DCC optical properties are retrieved from the measured signal in a reference band (typically B4 for Sentinel-2) considered as well calibrated and used to predict the TOA signal in the other bands to validate.

The DCC approach is statistical i.e. the method shall be applied on a large number of measurements to calculate reliable statistics and decrease the impact of perturbing contributors.

For more details about the methodology and the obtained results, please consult the following publication:

Nicolas Lamquin, Véronique Bruniquel & Ferran Gascon (2018) Sentinel-2 L1C radiometric validation using deep convective clouds observations, European Journal of Remote Sensing, 51:1, 11-27, DOI:10.1080/22797254.2017.1395713
Link to this article:  https://doi.org/10.1080/22797254.2017.1395713

Deep Convective Cloud observed by Sentinel-2A/MSI (RGB image)
Sentinel-2A mean inter-band gains (B4 as reference) for different DCC models (vertical distribution and ice cristal size)