Researchers at the Massachusetts Institute of Technology are developing an experimental radar system that will allow U.S. troops in combat to see through walls.
In recent tests held at MIT’s Lincoln Laboratory, the radar successfully showed humans moving behind solid concrete.
The researchers’ device is an unassuming array of antenna in two rows — eight receiving elements on top, 13 transmitting ones below — and some computing equipment, all mounted onto a movable cart. But project leader Gregory Charvat and his team believe the technology could have powerful implications for “urban combat situations.”
“If you’re in a high-risk combat situation, you don’t want one image every 20 minutes, and you don’t want to have to stand right next to a potentially dangerous building,” Charvat said.
Charvat envisions the unit mounted on a military vehicle and providing real-time video through walls as far as 60 feet away at a rate of 10.8 frames per second — far surpassing current technologies.
Humans and other animals see via waves of visible light that bounce off objects and then strike the retina. Light can’t pass through solid objects in quantities large enough for the eye to detect, of course.
"Rather than using visible light to look through walls, which is not very effective, we instead use a microwave,” Charvat explained.
X-ray would be perfect for this application, but its "ionizing radiation" is too dangerous, Charvat said. "We use microwave technology that’s about as powerful as a cellular phone, so it’s very weak. So, microwaves work. It’s not ideal, but it gets the job done."
The system does have limits, in other words.
“Eight inches is all we’ve been able to do,” Charvat said. Visibility “may be able to be increased by more transit power or lowering the frequency. The lower you go in frequency, the better it is, but it becomes a resolution issue.”
In time, the radar could be used by police or emergency-response teams, but the researchers said they developed the technology first and foremost for the military.
"This is meant for the urban war fighter … those situations where it's very stressful and it'd be great to know what's behind that wall," Charvat said.