[Source: CNES, Illustration by David DUCROS]
SpaceTech has acquired the C/D contract for the development of the Frequency Reference Unit (FRU) of the German-French methane gas mission MERLIN, in subcontract to Airbus DS Germany, responsible for the LIDAR instrument.
The MERLIN Satellite will monitor the global concentration of methane, one of the key climate changing trace gases in the atmosphere. The mission is a cooperation between DLR and CNES (Centre National d'Etudes Spatiales), now entering the realisation phase. The FRU provides the absolute frequency of the methane absorption feature at 1645 nm to the instrument and ensures the correct frequency of the high power laser pulses with which the actual LIDAR measurements are performed. It contains a methane gas cell, several frequency stabilised diode lasers, a wavemeter, and the electronics to achieve the actual closed loop control of all needed frequencies throughout the mission.