'Holy grail of leak detection': Researchers develop drone technique to tackle emissions
A group of Princeton University academics has created a novel technique to quickly identify major and minor leaks in sewage and gas drilling networks.
The laser-based sensing system can localize the emissions source to within a meter and correctly detect and quantify major greenhouse gas leaks, according to a university press release on Friday.
"Current approaches for detecting leaks often rely on handheld infrared cameras that are labor-intensive to operate and insensitive to small leaks, said Gerard Wysocki, associate professor of electrical and computer engineering at Princeton.
"They use methods that require setting up extensive measurement infrastructure ahead of time."
"But with a drone, you are completely free in how you are able to set up your sensing area," he added.
The system can as well detect leakage up to 25 times smaller than those generally found at natural gas facilities using conventional technologies.
Remote sensing capabilities of lasers and drone agility is the core of this new technology, which makes it simple to find leaks in difficult-to-access regions that would otherwise go undetected.
How does it work?

The new strategy uses a small drone that is merely equipped with a retroreflector, a kind of mirror that reflects incoming light back toward its source, and a base station with gas-detecting apparatus that can follow the drone's movements while it is in flight.
"That's really the holy grail of leak detection," said Mark Zondlo, study co-author, professor of civil and environmental engineering, and associated faculty at the Andlinger Center for Energy and the Environment.
The approach allows users to attach pricey gas-sensing components onto a transportable platform, like a van, in contrast to conventional drone-based techniques that call for mounting gas sensors directly onto a drone.
As a result, the drone can only carry a tiny mirror, which, when reflected from a potential leak, enables a user to identify the leak's origin and gauge its intensity.
The team's method makes it possible to collect extremely comprehensive emissions data across wide areas using smaller, less expensive drones with longer flight lengths.
Due to the technology's adaptability, it can monitor many gases at once, including ammonia and carbon dioxide, by adding additional lasers of various wavelengths to the base system.
"The most exciting thing is not simply the methane sensing abilities of the technology we developed," said Michael Soskind, the first author of the study and a graduate student in electrical and computer engineering, in the press release.
"It's really about unlocking the capability for researchers and practitioners to use drones and other remote sensing techniques to take detailed measurements of small leaks and reconstruct emissions plumes."