How digital mapping is uncovering the hidden past

Satellite imaging, drones and LiDAR become an essential part of the archaeologist’s toolkit

For years archaeologists unearthed the past using nothing more than a trowel and shovel. Today, however, they need to put some extra tools in their backpack: an ever-expanding range of tech-based mapping technologies.

A high-tech laser technique, known as LiDAR or light detection and ranging, is already rewriting the archaeological textbooks at an unprecedented rate, revealing for the first time ancient cities in Mexico and Guatemala, one the size of Manhattan.

Millions of laser pulses beam out from under an aircraft, penetrating the jungle canopy and bouncing back to create detailed topographical maps. Combine this with the latest geographical information systems and you can chart every detail of the earth’s surface with pinpoint accuracy, despite dense foliage.

“LiDAR is revolutionising archaeology the way the Hubble Space Telescope revolutionised astronomy,” Francisco Estrada-Belli, an archaeologist from Louisiana’s Tulane University told National Geographic.

Previously unknown Mayan structures including houses, fortifications and causeways have been identified, revealing a more densely populated, interconnected and sophisticated society than previously thought. The same tech has also been used to create 3D maps of civilisations at the site of Angkor Wat in Cambodia and the remnants of Iron Age society in Britain.

Archaeologists are also using other digital innovations. Geographical information systems have been used in Mexico’s Yucatán Peninsula to chart ancient Mayan settlements and how they correspond to the Chicxulub crater, a 110-mile-wide basin made by a meteor 64 million years ago. The ancient crater created a highly desirable environment for living in a region where water would otherwise be non-existent.

Every time we get a new imaging technique that does not include excavation, which is expensive and destructive, it’s always a plus

Archaeologists looking for an overhead view have been using satellite imagery for some years now, but robotic drones are now coming into their own. Equipped with thermal imaging cameras and mapping instruments they are able to chart vast sites. This has resulted in several significant discoveries in Asia, South America and the Middle East, including a giant stone platform, twice the size of an Olympic swimming pool, thinly hidden by sand in the ancient city of Petra in Jordan.

“Every time we get a new imaging technique that does not include excavation, which is expensive and destructive, it’s always a plus. It allows us to see new things,” says Mark Schurr, a professor of anthropology of the University of Notre Dame told Associated Press.

An award-winning journalist and broadcaster, Nick Easen writes on science, technology, economics and business. He has produced content for BBC World News, CNN, Time magazine, Bloomberg, CNBC, The Times, Guardian and Telegraph.