Methane's heat trapping can range between 25 and 86 times worse than carbon dioxide, depending on the time period over which it's considered. Fugitive methane leaks from large pipelines are a major contributor to this problem.
This sweet little unmanned aerial vehicle (UAV) was developed at the Jet Propulsion Lab in Pasadena (JPL) and the Mechatronics, Embedded Systems and Automation Lab (MESA) at the University of California, Merced as part of a project to improve safety for energy pipelines.
It’s equipped with a sensor that can detect methane in lower concentrations (think parts per billion) than other available field detectors as the gas leaks from pipelines.
The sensor is actually modified from a type used by NASA on Mars. It’s based on an Open Path Laser Spectrometer (OPLS). OPLSs operate by directing a very specific wavelength of light through atmosphere at a reflector to increase the path length as far as reasonably possible and then sending it back to a receiver.
The light wavelength is specifically chosen and tuned to be absorbed by the gas molecule of interest. Using Beer's Absorption Law and feeding it the resulting multipath light intensity, the gas concentration can be very accurately calculated down to very low concentrations.
It's likely that the OPLS system will be adapted into fixed-wing UAVs to allow pipeline surveys that could extend hundreds of miles owing to better fixed-wing endurance.
At refineries and other geographically large complexes, fugitive methane surveys often come down to hand-measuring methane in a small representative area and the results are then extrapolated to the entire multi-acre facility. With a multi-rotor UAV, actual flyover surveys that accurately map an entire facility could provide a much more reliable result.
It won't be long before flatulent cows will have to look over their shoulders!
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