The latest technology enables scanning of faces in 3D from hundreds of meters away

After 325 meters apart, your eyes can probably distinguish a person’s head from the body. However, new laser-based devices can create three-dimensional models of faces.

Aongus McCarthy The University of Heriot Watt in Scotland and his colleagues have built a device that can create detailed three-dimensional images containing 1 millimeter ridges and indents a few hundred meters apart. An imaging technique called Lidar is used to emit pulses of laser light, collide with the object and is reflected on the device. Based on how long it takes each pulse to return, Lidar can determine the shape of the object.

To reach this level of detail, the team had to carefully tune and align many different components, McCarthy said, including small parts that direct the laser pulse into the device. To enable discrimination between single light particles, the researchers used photodetectors based on extremely thin superconducting wires, a component not common in LIDAR. Exclude sunlight that could enter the detector and break down the image was another challenge.

Researchers tested the rider system on a roof near the lab by taking detailed three-dimensional images of the team members’ heads from 45 meters and 325 meters apart. On a small scale, they captured LEGO figurines from a distance of 32 meters.

Another test imaged a segment of a communications tower one kilometre away. “It was a very difficult test. I couldn’t control what the scene could do due to the bright background. [that we were imaging]McCarthy says.

Feihu Xu At the University of Science and Technology in China, the team previously used LIDAR for imaging From 200km awayMcCarthy and his colleagues say they achieved “amazing results” in terms of the device’s depth resolution. “It’s the best so far,” he says.

Lidar says that modern technology is only becoming more relevant Vivek Goyal at Boston University, Massachusetts. He says that being able to create detailed 3D maps of the surroundings is also important for self-driving cars and some robots, but before using them for this purpose, new devices need to be made smaller and more compact. There is.