CO2 Airborne Lidar Enabling Science for Carbon Efficiently (COALESCE)

This proposal seeks to verify the feasibility of developing a small, low power, airborne, CO2 lidar that would be capable of sharing resources with NASA’s High Altitude Lidar Observatory (HALO) instrument, enabling simultaneous measurement of CO2 and CH4 without the expense of hosting a separate instrument on an additional port of a NASA research aircraft. The basis for this work is the Multifunctional Fiber Laser Lidar (MFLL), originally developed by ITT Space Systems (now L3Harris Technologies) as an airborne prototype to evaluate a novel intensity modulated continuous wave (IMCW) measurement approach that leverages high-reliability telecommunications components and techniques to achieve a high-accuracy measurement of CO2 in an integrated-path differential absorption (IPDA) measurement [Dobbs, 2007; Dobler, 2013]. This unique approach enables continuous online and offline measurements which share many of the same noise sources from amplification, atmospheric scintillation, surface reflectivity changes and receiver electronics, of which the multiplicative components cancel out in the ratio of the channels used to determine the differential absorption. MFLL was selected as a key instrument in the NASA Earth Venture Suborbital mission Atmospheric Carbon Transport - America (ACT-America) mission, conducting 89 flights over 4 extensive field campaigns between 2016 and 2020. The results of this work showed very high accuracy CO2 measurements could be made using this technique [Campbell et al., 2020]. The MFLL instrument data from ACT-America has also enabled improved algorithms for OCO-2 [Bell, 2020; Baker, 2022] and unique insights into CO2 variations across frontal boundaries [Pal, 2020; Walley, 2022].