Researchers in China have developed a lidar-based system that can capture images of humans at huge distances, even through thick pollution.
A team from the University of Science and Technology in Shanghai created a system that can capture subjects at a distance of 28 miles using sensors capable of detecting a single photon, together with an algorithm that 'knits' together sparse data points to create a high resolution image.
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The system works in a similar way to lidar, sending out a pulse of laser light and then mapping the light that bounces back. This technique means it's able to record images even through the smog that's a huge problem in densely populated cities.
Looking to the future
The system could be hugely important for autonomous cars, which rely on cameras to detect and predict the movements of vehicles and pedestrians, but would be rendered useless by severe pollution.
This will be particularly important for cities like Shanghai, where vehicle automation could lead to a huge improvement in air quality. Automakers around the world are planning fleets of autonomous taxis, which would reduce the need for privately owned cars, and therefore cut pollution on city streets.