New device can scan your face in 3D from hundreds of metres away

From 325 metres away, your eyes can probably distinguish a person's head from their body – and not much else. But a new laser-based device can create a three-dimensional model of their face. Aongus McCarthy at Heriot-Watt University in Scotland and his colleagues built a device that can create detailed three-dimensional images, including ridges and indentations as small as 1 millimetre, from hundreds of metres away. It uses an imaging technique called lidar, emitting pulses of laser light that collide with objects then reflect back into the device. Based on how long each pulse takes to return, lidar can determine an object's shape.