The Sentinel-2 mission is part of the EU Copernicus program. The Multi Spectral Imager (MSI) is the main instrument of this mission and aims at providing high spatial resolution and multi-spectral images dedicated to the monitoring of land and coastal areas. The instrument owns 13 channels in the visible/near (VNIR) and short wave infrared spectral range (SWIR). Silicon carbide is used to ensure highest stability on the telescope and the SWIR detector conductive coupling to its radiator via a cold finger. One of the main challenges is to passively control the SWIR focal plane assembly at 195 K while the rest of the instrument is finely regulated at room temperature.
Taking benefit from about 4 years of precious data on Sentinel-2A (launched in June 2015) and 2,5 years on Sentinel 2-B (launched in March 2017 on S-2B) a joint in-flight thermal correlation and characterisation exercise was carried out by Airbus Friedrichshafen and Airbus Toulouse (lead by ESA).
This presentation will describe the main challenges and conclusions of this activity focusing on the instrument point of view (satellite results will be presented separately), including:
- Methods for analysing instrument in-orbit data during the whole lifetime of a system, including study of thermal behaviour of the instrument
- Comparison of behaviour between instrument models (S-2A versus S-2B)
- Integration of in-orbit data into thermal simulations
- Correlation of thermal models with in-orbit measurements and discussion on how the thermal validation sequence on ground could be improved
- Summary of lessons learned from the project for future instruments