Scientists, archaeologists and foresters are using pulses of laser energy beamed down from aircraft flying about 1,000 metres up to reveal a forest's hidden secrets. These can include sites of ancient settlements, fortifications, farms and other signsof human activity which, in woodland, are often difficult to detect from the ground or the air with the naked eye. The system is called 'lidar' (light detection and ranging) and the technology works by 'bouncing' harmless laser energy off the forest inmuch the same way as radar bounces radio waves off solid objects.
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