When toxic gasses leak into the atmosphere, they are impossible to see with the naked eye, posing a major threat to public safety. But now, engineers and chemists at the University of Colorado Boulder are working on a technology that will help detect chemical threats before it’s too late.
The research project is called the Standoff Aerosol measUrement Remote Optical Network, or loosely, SAURON. It’s a playful nod to the , a villain in the Lord of The Rings books and movies who could see everything.
“We had to stretch a little bit for the U, which is in the middle of the word measurement, but we made it work,” said Greg Rieker, the principal investigator at the University of Colorado Boulder. “In the Lord of the Rings, Sauron is, of course, an evil character. Here, we're really trying to develop something that's good for people and it keeps them safe.”
Here’s how it works: a radar-like technology is mounted to a tower and sends out a laser once every hour. That light is not like the red laser pointers you see in an office, but rather it’s the called a frequency comb laser which emits thousands, if not millions of colors of light. It’s also an invisible light, so it is eye-safe.
Every gas in the atmosphere has a specific “signature,” or set of colors of light that it interacts with on a molecular level. Depending on what exact colors of light are absorbed, researchers can identify what gasses are in the atmosphere when the light is reflected back to the transceiver.
“When the light comes back, if some of that light is missing, we know that we found methane along the way,” Rieker said. “The same is true for aerosols, these tiny droplets of liquid, or other gasses, like Benzene or Toluene are different gasses that might be dangerous for people.”
The technology then alerts industries about the presence of the gas so they can go and fix leaks quickly. The end goal is to position more “SAURONS” around a city to consistently monitor an area for any harmful chemical activity.
Rieker co-founded Boulder-based , which has commercialized technology to identify methane. Several oil and gas industries in Northern Colorado currently use dozens of these monitoring towers. Each tower reaches an 8-10 square mile region.
But there are many other gasses that researchers want to spot. Through Rieker’s work at CU Boulder, he wants to expand the radar’s capabilities to detect other dangerous gasses for security and defense purposes, like detecting dirty bombs or other chemical warfare.

“So if there's a harmful cloud of aerosols that has been released or is in an area, they'd like to be able to look into that cloud of aerosols and be able to tell quickly, like, what is it?” he said.
So far, the team has found success in detecting the other gasses over short distances in the lab and they plan to scale it up to larger distances in the future.
“If we continue to do well as we are right now, this is a system that could be commercially available on that few year timescale,” Rieker said. “It’s gonna be real.”
The project has received millions of dollars in funding from the – part of the federal Office of the Director of National Intelligence – to do the research for the next three and a half years. The CU Boulder team is also working with the California Institute of Technology, the University of California Santa Barbara, and three companies, including LongPath Technologies.
At the end of the day, Rieker wants people to know that his team is not building something sinister that Frodo has to come and defeat.
“I want people not to be scared of this, but to feel safer, knowing that someday they might have their own Eye of Sauron watching over them,” Rieker said.