Slashdot Mirror
Seeing Through Walls
An anonymous reader writes "Researchers at MIT's Lincoln Lab have developed new radar technology that provides real-time video of what's going on behind solid walls. 'The researchers’ device is an unassuming array of antenna arranged into two rows — eight receiving elements on top, 13 transmitting ones below — and some computing equipment, all mounted onto a movable cart. But it has powerful implications for military operations, especially "urban combat situations," says Gregory Charvat, technical staff at Lincoln Lab and the leader of the project.' ... each time the waves hit the wall, the concrete blocks more than 99 percent of them from passing through. And that’s only half the battle: Once the waves bounce off any targets, they must pass back through the wall to reach the radar’s receivers — and again, 99 percent don’t make it. By the time it hits the receivers, the signal is reduced to about 0.0025 percent of its original strength. But according to Charvat, signal loss from the wall is not even the main challenge. "[Signal] amplifiers are cheap," he says. What has been difficult for through-wall radar systems is achieving the speed, resolution and range necessary to be useful in real time (PDF).'"
Is the amount of radiation dangerous? What about reflections? Not that it would matter in a military context but it might restrict its civilian applications.
Two points:
A) This is different than x-ray because it is using the reflection, not a film or detector on the other side of the object.
C) The image created is not a 3D image like what you would expect if the wall were glass, instead it detects distance to objects. So what you get is like a overhead map, as if you were playing Zelda and or had the Harry Potter marauder's map. Which may be more useful in some situations.
"First they came for the slanderers and i said nothing."
The wall already shines conspicuously in the radar beam. They had to put an analog filter into the receiving equipment to block out the massive return they get from the wall itself so it doesn't overpower their A/D. At most, you would be able to tell "there might be something of interest behind this wall... or maybe its just a sheet of metal...".