Title: Lidar-based gas analyzer for remote sensing of atmospheric methane

Abstract: Enhancement of methane emission measurement techniques is necessary to address the need for greenhouse gas emissions monitoring. Here we introduce a gas analyzer designed for remote sensing of atmospheric methane aboard unmanned aerial vehicles. This device employs the wavelength modulation spectroscopy approach and quadrature detection of laser radiation scattered from the underlying surface. Our results demonstrate that the observed correlation between various signal attributes and the distance to the surface, where laser radiation scatters, aligns with analytical expectations. Calibrations proved that the instrument provides reliable methane measurements up to 120 meters while being lightweight and power efficient. Notably, this device outperforms its competitors at altitudes exceeding 50 meters, which is safer for piloting.