October 2003

3-D Sky Eye

By David Talbot

Military jets need it now. Robots and cars will need something similar in the future: a rugged "vision" system that can produce sharp 3-D images of terrain contours and objects, day or night. This summer, researchers at MIT's Lincoln Laboratory in Lexington, MA, made the first test flights of a 3-D laser imager that can do precisely that.

The new technology uses extremely fast infrared lasers and unique arrays of ultrasensitive light detectors. The laser-emitted light reflects off of objects, and the time it takes to return is measured by detectors, providing a 3-D image. The arrays capture 10,000 images per second and can detect even one photon, says Rick Heinrichs, physicist and group leader at Lincoln Laboratory.

That improves on existing 3-D laser imagers, which scan across a target and more slowly piece together an image, which limits resolution and the ability to visualize partly obscured objects through foliage, for example. What's more, the new arrays "don't have moving parts, making them ultimately cheaper and more reliable," says Maris Juberts, an electrical engineer at the National Institute of Standards and Technology in Gaithersburg, MD.

Of course, "it's going to be a while before this goes to Detroit, because the costs have to go down," says Heinrichs. But already, the airborne version of the imager is seeing the targets through the trees.