ESA terahertz sensing technology finds its place in the Los Angeles Metro system
Terahertz imaging technology patented by the European Space Agency (ESA) is being placed at various locations in the Los Angeles, CA Metro system as security equipment to detect concealed weapons or explosives. The new screening cameras can detect both metallic and nonmetallic objects on a person’s body. They are capable of screening up to 2000 passengers per hour.
The LA Metro will become the first mass transit system in the United States to install people-screening technology. The machines incorporate technology originally developed by ESA to help understand galactic evolution.
Developed by Thruvision (Oxford, UK), the body scanners are noninvasive, passively screening individuals for suspicious objects. Human bodies (and anything else warm) emit terahertz radiation; the Thruvision sensors work by detecting the absence of the naturally occurring terahertz waves. "When an object is hidden in clothing or strapped to a person, these waves are blocked and their absence is detected by the system’s software," says Stefan Hale, CEO of Thruvision. "The technology does not emit radiation of any kind and no anatomical details are displayed."
The first working terahertz camera was developed in the early 2000s by an ESA-led team working out of the Rutherford Appleton Laboratory in the UK, aimed at future space missions. Several team members went on to start Thruvision to spin off the technology for terrestrial uses.
"Observing galaxies in the terahertz range can help us better understand how they were formed in the early Universe, and how stars have formed throughout history," says ESA engineer Peter de Maagt, who led the original team. "And in environmental monitoring, these frequencies can reveal details of ozone depletion as well as helping us understand global climate change."
Thruvision acquired rights to the ESA-patented terahertz technology to develop a people-screening capability, and today have more than 300 cameras deployed in 18 countries around the world. The Thruvision cameras put in place in the LA Metro will be able to screen people and spot hidden objects at up to 10 meters away while passengers simply walk past the system, without any slowdown in their daily commute.
The terahertz technology is part of ESA's intellectual property rights portfolio consisting of around 450 patents based on space innovations, available for licensing by European companies for space and terrestrial applications. The portfolio is managed through the Agency’s Technology Transfer and Business Incubation Office, finding down-to-Earth uses for advanced space technology.
John Wallace | Senior Technical Editor (1998-2022)
John Wallace was with Laser Focus World for nearly 25 years, retiring in late June 2022. He obtained a bachelor's degree in mechanical engineering and physics at Rutgers University and a master's in optical engineering at the University of Rochester. Before becoming an editor, John worked as an engineer at RCA, Exxon, Eastman Kodak, and GCA Corporation.