Greenhouse Gas Sensing Using Small Unmanned Aerial Systems – Field Experiment Results and Future Directions

Abstract:

Requirements for greenhouse gas point source detection and quantification often require high spatial resolution on the order of meters. These applications, which help close the gap in emissions estimate uncertainties, also demand sensing with high sensitivity and in a fashion that accounts for spatiotemporal variability on the order of seconds to minutes. Low-cost vertical takeoff and landing (VTOL) small unmanned aerial systems (sUAS) provide a means to detect and identify the location of point source gas emissions while offering ease of deployment and high maneuverability. Our current fielded gas sensing sUAS platforms are able to provide instantaneous in situ concentration measurements at locations within line of sight of the operator. Recent results from field experiments demonstrating methane detection and plume characterization will be discussed here, including performance assessment conducted via a controlled release experiment in 2013. The logical extension of sUAS gas concentration measurement is quantification of flux rate. We will discuss the preliminary strategy for quantitative flux determination, including intrinsic challenges and heritage from airborne science campaigns, associated with this point source flux quantification. This system approach forms the basis for intelligent autonomous quantitative characterization of gas plumes, which holds great value for applications in commercial, regulatory, and safety environments.