A Space Borne Lidar Instrument for Methane: Instrument Monitoring & Quality Assurance

The concentration of methane (CH 4 ) with other greenhouse gases in the atmosphere lead to the raise of the mean Earth surface temperature. Methane is in fact the most important greenhouse gas in the atmosphere after H 2 O and CO 2 , with emission from anthropogenic and natural processes. Global observations and monitoring with high accuracy and spatial resolution to track down its sources and sinks on a global scale are however necessary, but yet challenging.The active space borne Lidar instrument MERLIN (Methane Remote Sensing Lidar Mission) will provide new sensitive measurements of methane distribution with unprecedented quality, with a precision <2%. In this paper, we present our approach to perform a key ground segment task that will support MERLIN scientific activities which is the long-term monitoring of the Lidar instrument and its performance. The instrument long term monitoring task will track the measurements quality and the performance of the instrument and its subsystems on a daily up to a monthly basis over MERLIN mission lifetime.