3D laser scanner can capture objects over half a mile away

The researchers developed a technique which uses advanced laser technology to scan almost any object. With extra research, it is estimated that the camera's range could extend to as much as 10km (6.2 miles). The system works by sweeping a low power infrared laser beam rapidly over an object. It then records, pixel by pixel, the round trip flight time of the photons in the beam as they bounce off the object and arrive back at the source. The system can resolve depth on the millimetre scale over long distances using a detector that can 'count' individual photons. Its primary use is expected to be in scanning static, human-made objects, such as vehicles. With some modifications to the image-processing software, the researchers say it could also determine their speed and direction. Dr Aongus McCarthy, a research fellow at Heriot-Watt, noted: "Our approach gives a low power route to the depth imaging of ordinary, small targets at very long range. "While it is possible that other depth ranging techniques will match or out perform some characteristics of these measurements, this single photon counting approach gives a unique trade off between depth resolution, range, data acquisition time and laser power levels."