Meteosat Third Generation (MTG) is the future European operational geostationary meteorological system that will replace the Meteosat Second Generation System (MSG) at the end of its operational life.

The objective of MTG mission is to provide Europe, by extension, the International Community, with an operational satellite system able to support accurate prediction of meteorological phenomena and the monitoring of climate and air composition through operational applications for the period of time between 2017 and 2037.

This mission will be fulfilled by series of four imaging satellites MTG-I (hosting the Flexible Combined Imager (FCI) and the Lightning Imager (LI)) and two sounding satellites MTG-S (hosting the Infrared Sounder (IRS) and accommodating the Sentinel 4 UVN instrument) for a minimum of 20 years nominal operational lifetime.


The CSL is involved in the instrument called the Back Telescope Assembly (BTA), which is a sub-assembly of the IRS instrument on MTG-S. It is an afocal telescope operating at 0°C.


The BTA will be jointly developed by AMOS and CSL.


The CSL responsibilities in this project are :

  • The thermal design and analyses
  • The mirror optical coatings and associated test performances
  • The OGSE and optical characterization of the BTA
  • The AIV and environment tests.




BTA mounted on the front telescope optical bench assembly

Contact(s) : Isabelle Tychon