Cameras can detect and track moving objects hidden from view

A new study published in the journal Nature Photonics on December 7 is suggesting that lasers can help cameras in tracking moving objects hidden around corners. Soon, we might see this finding help vehicles in seeing around blind corners for avoiding collisions.

These days, use of laser scanners for capturing 3D images of objects is pretty common. These scanners work by bouncing pulses of light off different targets, and as light always travel at the same speed, the devices succeed in measuring the time required for the pulses to come back. This particular measurement reveals the exact distance covered by the light pulses, and thus, it can be used for recreating the three-dimensional appearance of the object in question.

Previous research suggested that lasers fire pulses of light at surfaces near the objects hidden around corners in order to locate them. These surfaces play the role or mirrors by scattering the light fired on them onto different obscured targets. During the study, researchers analyzed the light reflected off the objects and other surrounding surfaces back to the laser scanner for reconstructing the exact shapes of the objects.

Daniele Faccio, a senior author of the previous study, said that this ability of lasers to allow us to see what’s behind the wall is remarkable. Faccio is a physicist representing the Edinburgh, Scotland-based Heriot-Watt University.

One of the most prominent applications of this study can be in systems that can assist vehicles in seeing around the bends for avoiding impending collisions.

Faccio said that if a person or another vehicle approaches towards a car at an extremely high speed and thereby increases the risk of a collision, the laser-based system can perform the job of informing the car about that impending risk. Faccio added that upon getting the information, the car would decide to slow down autonomously.

However, there was a major weakness of the previous research. The system tested in it took a lot of time for reconstructing the image. This stopped the researchers from using the system for tracking moving objects in real time.

The new study has allowed scientists to find a way of seeing moving objects hidden around corners in just a few seconds instead of a few hours.

The new system involves the use of a camera and a laser. The laser the researchers have used was amazingly fast; it possesses the ability to fire as many as 67 million pulses in a second; each of those pulse last for just 10 femtoseconds. For those who don’t know: a femtosecond is equivalent to a millionth of a billionth of a second.

The camera used by the researchers, on the other hand, is extremely sensitive and can detect single packets of light or photons. It can capture the packets of light every 50 picoseconds. One picosecond is a millionth of a millionth of a second.

Due to such high sensitivity and speed of the camera, the researchers could locate hidden objects within just 3 seconds of capturing data pertaining to them.