Lasers Are Creating An Archaeological Revolution

From Maya cities to Stonehenge’s plains, airborne laser scanning is revealing ancient secrets around the globe.

Hundreds of thousands of people travel to Cambodia to see Angkor Wat every year, but new research shows there could soon be a lot more to see at the largest religious complex on Earth.

Using light detection and ranging scanners, known as LiDAR, scientists have discovered the vast scale of Khmer Empire’s sprawl, showing Angkor Wat once supported a massive network of cities that would even rival Phnom Penh, Cambodia’s modern-day capital.

A quiet revolution in archaeology has resulted from LiDAR's advent, with scholars making new discoveries by using the technology to look at Maya cities, Stonehenge's plains, and Renaissance palaces, among other places.

Terrain around the central monuments of Sambor Prei Kuk

A new image from the survey shows the terrain around the central monuments of Sambor Prei Kuk

The airborne technology bounces laser light pulses off the ground to generate precise pictures of surface features.

Katharine Johnson of the University of Connecticut, has LiDAR to reveal "numerous archaeological sites" in three areas of Connecticut and Massachusetts – the landscape made famous by some of North America's earliest European settlers.

“Similar to seeing Maya pyramids emerging from the forest, we can see sites that we couldn't any other way. I literally walk into the woods with GPS coordinates from LiDAR and find a foundation I would never have imagined was there,” says Johnson.

“With LiDAR, we can actually do area surveys that show comprehensively what was once there, not just what has turned up randomly over time.”

While we can expect many more important archaeological discoveries using LiDAR, it does have its limitations.

“Native Americans didn't leave behind walls and foundations in New England. LiDAR can't tell us as much directly about their era.”

EXPLORE FOR MORE: Excavation of Ancient Lost City Yields New Finds

The Future of Seeing the Past

In some ways, it’s becoming easier than ever to connect people to the past. Smartphones and tablets can already display compelling, three-dimensional explorations in real time.

“The future of preservation is to refrain from excavation,” says Cristina Corsi, an archaeologist at the University of Cassino in Italy.

But for some people, there’s no replacing the real thing.

“Among tourists [looking at a site remotely], you have the impression that they feel robbed [of] the possibility to touch and see monuments,” notes Corsi.

In some places, however, that’s not an option. Many cities, especially in Europe, have long histories of building on top of archaeological sites. In those cases, noninvasive research techniques may be the only way to dig into former times.

Cornelius Meyer, a geophysicist and managing director of the geo-prospecting firm Eastern Atlas, based in Berlin, says it’s now possible to see beneath many places—airports, roads, church floors, town squares—that were inaccessible in the past. And, he says, “we still have a lot of unexplored archaeological sites” that are primed for a digital discovery. 

As non-invasive research methods grow more prevalent, the expense and danger of disturbing ancient sites may itself become a relic of the past.

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