MIT's Lincoln Laboratory researchers announced they developed a new radar technology that can "look" through concrete walls, a capability the scientists hope will soon help troops in urban combat, and be adapted for emergency responder use amid disasters.
Humans see by receiving waves of visible spectrum light bouncing off objects, and radar systems bounce radio waves off objects for receivers to "see" -- but detecting electromagnetic waves in the visible or radio wave ranges through building walls and other solid objects has long-challenged technicians because light and radio waves do not pass through sold objects in quantities large enough for human eyes or radar receivers to detect; now Lincoln Lab researchers have devised a new system that can penetrate walls and form instant images of what is happening behind them from stand-off distances, ScienceDaily reported.
The new device, attached to a movable cart, is an uncomplicated array of two rows of antennas -- 13 transmitters below and eight receivers on top -- connected to computers.
Project leader Gregory Charvat explained that signal loss, both penetrating the wall and returning, can be solved by adding relatively inexpensive amplifiers, but developing a system with enough range, resolution and speed to be useful in action presented the greatest challenge:
“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.”
Lincoln Labs, MIT
The "through-wall ultrawideband radar" system developed by MIT's Lincoln Labs sees through buildings; this picture shows an experimental set up of the system.
Using S-band waves, the range used by Wi-Fi, Lincoln Lab’s system, which is about eight and a half feet long, generates real-time video images of motion behind walls up to 60 feet away at 10.8 frames per second; the team tested the device at 20 feet, a realistic range for urban combat situations, according to the team.
The system's computer processor works by a subtraction method that compares new pictures to previous shots and analyzes what changes, so the new radar only detects moving targets making even small motions -- furniture would not show in the display, but human locations would appear as moving "blobs" in a birds-eye view.
A next step is tweaking the algorithms to automatically interpret the blobs as clear, user-friendly symbols.
The team recently presented and published a paper detailing their through-wall radar imaging system.