Low-Altitude Aerial Methane Concentration Mapping

Abstract

Detection of leaks of fugitive greenhouse gases (GHGs) from landfills and natural gas infrastructure is critical for not only their safe operation but also for protecting the environment. Current inspection practices involve moving a methane detector within the target area by a person or vehicle. This procedure is dangerous, time consuming, labor intensive and above all unavailable when access to the desired area is limited. Remote sensing by an unmanned aerial vehicle (UAV) equipped with a methane detector is a cost-effective and fast method for methane detection and monitoring, especially for vast and remote areas. This paper describes the integration of an off-the-shelf laser-based methane detector into a multi-rotor UAV and demonstrates its efficacy in generating an aerial methane concentration map of a landfill. The UAV flies a preset flight path measuring methane concentrations in a vertical air column between the UAV and the ground surface. Measurements were taken at 10 Hz giving a typical distance between measurements of 0.2 m when flying at 2 m/s. The UAV was set to fly at 25 to 30 m above the ground. We conclude that besides its utility in landfill monitoring, the proposed method is ready for other environmental applications as well as the inspection of natural gas infrastructure that can release methane with much higher concentrations.

A review of close-range and screening technologies for mitigating fugitive methane emissions in upstream oil and gas

“…One of the primary advantages of UAVs is that they are uniquely suited to characterizing methane plumes in three dimensions while flying in close proximity to the source, improving confidence in attribution. To date, various attempts have been made to measure methane from a UAV (Khan et al 2012, Brownlow et al 2016, Barchyn et al 2017, Cossel et al 2017, Emran et al 2017, Smith et al 2017. The first comprehensive study investigating UAV methanesensing potential focused on a single compressor station, which was monitored over a one-week period by a fixed-wing UAV (Nathan et al 2015).…”

Methane Mitigation: Methods to Reduce Emissions, on the Path to the Paris Agreement

“…Further marked improvement in the precision, price, and availability of UAV-mounted sensors should be expected in the near future. Small drone-carried sensors have much promise for safe close-up mapping of air with high methane mole fractions around major leaks, for example, in mapping the 3-D distribution of a plume from a leaking gas installation, and hence quantifying the flux (Emran et al, 2017).…”

Detection of Gas Drifting Near the Ground by Drone Hovering Over: Using Airflow Generated by Two Connected Quadcopters

“…However, even an affordable metal oxide gas sensor showed some response when a hexacopter was made to fly at a relatively low altitude over a gas source [10]. A hexacopter equipped with a laser-based remote methane detector [11] was able to detect methane emission from the ground even from 25 m above a landfill site [12]. A gas distribution map can be obtained by scanning the area of interest with a multicopter equipped with such a gas detection device [10,12,13].…”

“…A hexacopter equipped with a laser-based remote methane detector [11] was able to detect methane emission from the ground even from 25 m above a landfill site [12]. A gas distribution map can be obtained by scanning the area of interest with a multicopter equipped with such a gas detection device [10,12,13]. Neumann et al reported results of gas source localization experiments using a quadcopter equipped with several different types of gas sensors (metal oxide, electrochemical, catalytic, and infrared sensors) [14].…”