updated 05:15 pm EDT, Wed March 21, 2012
MIT scientists able to peer at objects behind wall
Scientists have published a paper in Nature outlining a way to take pictures of things that is hidden away and not in the camera's line of sight. The researchers, operating out of the Camera Culture Research Group at the MIT Media Lab, use echoes of laser-generated light pulses and sophisticated software to peer around corners and recreate an image of an object. The algorithm is similar to those used in generating CAT-scan images.
To create an image, a laser fires a pulse at a wall on the far side of the object. When the beam hits the wall, it is scattered as individual photons. The camera then records the how much time it takes the units of light to echo or bounce back to the camera. The camera is actually recording multiple photon streams. As the laser emits the light, it is simultaneously being repositioned 60 times. This gives the image dimensionality and perspective.
The duration of the laser pulse is extremely short, only 50-femtoseconds, or 50 quadrillionths of a second. The algorithm then factors in how much time it takes for the photons to bounce back from the object and draw a graphic representation of the hidden object. Currently, it takes several minutes to shoot the laser pulse and process the echoes. In the future, the scientists hope to reduce the time to under ten seconds.
Possible applications include looking around walls in contaminated sites, or even into machinery while it's operating. [via Digital Trends]