Jeffrey S Rutherford, Evan David Sherwin , Yuanlei Chen , Sam Aminfard, Adam R Brandt 

Methane (CH4) from oil and gas (O&G) activities is a known contributor to global anthropogenic methane emissions and recent research has demonstrated that a small fraction of large emitters contribute to the majority of total emissions. In this study, we perform a single-blind evaluation of the quantification capabilities of three airplane-based technologies (Bridger Photonics’ Gas Mapping LiDAR, Carbon Mapper’s Global Airborne Observatory, and GHGSat-AV) with a focus on large emitters (10-2,000+ kg h-1 CH4). In two 2021 campaigns, metered natural gas was released concurrently with overpasses by the tested technologies. Results were submitted by operators in a three-stage unblinding process. All teams detected 100% of releases above 50 kg h-1 CH4. The teams report parity slopes of 0.35 to 1.06, with R2 values of 0.35 to 0.78. After 10-meter anemometer wind measurements were unblinded, two out of three teams significantly reduced variance in the parity slope, highlighting the importance of accurate wind data. After half of metered release volumes were subsequently unblinded, improvement was mixed. These results suggest that multiple commercially available technologies can reliably detect larger point-source methane emissions, with varying quantification performance and trade-offs between survey area coverage and instrument sensitivity.