Now there’s no safe place to hide – even in seemingly blind corners.
Through the help of lasers, cameras can now track moving things hidden around corners and, in the future, assist drivers in working their vehicles around bends to prevent colliding with other motorists and even pedestrians.
Laser scanners capture three-dimensional images of objects, bouncing light pulses off targets. They can measure the time of the pulses’ return journey and how far they have traveled, which in turn allows one to recreate how the objects appear in 3D.
Lasers fire light pulses at surfaces near objects hidden around corners. The surfaces can serve as mirrors that scatter light onto difficult targets, and researchers can analyze the light and reconstruct the objects’ shapes.
"The ability to see behind a wall is rather remarkable," said Scottish physicist Daniele Faccio, a physicist and senior author of the study published Dec. 7 in the journal Nature Photonics.
The groundbreaking system is composed of an outstandingly fast laser able to fire 67 million pulses per second, as well as a camera with high sensitivity to detect single photons - particles that transmit light - that is quick enough to capture these packets of light every 50 picoseconds (one-millionth of one-millionth of every second).
Previous studies exhibited similar action, but were challenged by the length of time needed in the reconstruction of an object's image. Now, researchers have devised a way to see objects moving behind corners in seconds rather than hours.
Author Genevieve Gariepy, also hailing from Heriot-Watt University, said that while most other scientists were attempting to reconstruct in 3D, their team was focused on tracking. “We developed new algorithms to be able to achieve this, and achieve it fast,” she recounted.
The team’s experiments fired laser pulses onto a white cardboard floor fronting a black cardboard corner. The hidden item was a foam human statue, data on which was captured by the camera after a mere three seconds. The precision was up to 0.4 inches.
However, the technology cannot generate the objects’ 3D images yet, only provide the location. In the future, Faccio and his colleagues are hoping to make the system see in full 3D and detect items hundreds of feet in distance and faster than the current three seconds.
The potential uses of this laser spy camera include serving as an early warning device for cars that turn into blind corners, along with scanning buildings during search-and-rescue missions.
See the laser camera system in action below.
Photo: Nayu Kim | Flickr
