LIDAR is not something you may have heard of, but its affect on our knowledge of ancient history has been utterly staggering.
Light Detection and Ranging is a geographical mapping technique that uses giant satellite-mounted lasers to cut through jungles and environmental barriers to map the Earth's surface.
Since its introduction it has saved years of fruitless exploration by mapping huge swathes of land revealing hidden buildings, landmarks and in the case of Cambodia, an entire city.
The ancient medieval city of Angkor was initially discovered through years of hard labour and excavation, however the introduction of LIDAR allowed a team of scientists to discover an even larger city hidden in the undergrowth simply by flying a helicopter over the jungle.
By firing a million laser beams every four seconds from the bottom of the helicopter LIDAR was able to map the real city of Angkor revealing it as the greatest example of a Medieval city in the world with a size of over 1,000km.
Since then the technology has progressed even further with LIDAR now coming courtesy of satellites. LIDAR isn't cheap ($350 per sq km) but in comparison to the years of manpower that'd be required to discover these locations in the first place it's a price that universities are more than happy to pay.
Discovery News has done a rather informative feature (see above) expanding on the use of LIDAR and showing just how revolutionary it has become.Suggest a correction