Archaeologists and adventure junkies are buzzing about the announcement of previously unknown ruins of a complex Maya settlement hidden for centuries amidst the jungles of Guatemala.
Researchers at the National Center for Airborne Laser Mapping, or NCALM, say the discovery of tens of thousands Maya structures (temples and houses), sophisticated agricultural systems and other human-made features and a huge increase in population estimates wasn’t the result of luck or technological voodoo. It was instead the latest research-based reporting using airborne light detection and ranging technology, or LiDAR.
The findings, described in a documentary set to air on the National Geographic television channel Tuesday, offer a vivid illustration of the way in which LiDAR has expanded the discipline of archaeology, providing a birds-eye view of ancient sites that are far more difficult to survey on the ground.
NCALM is based at the University of Houston and jointly operated by UH and the University of California at Berkeley.
Portions of the ruins showcased in “Lost Treasures of the Maya Snake Kings” had already been documented by archaeologists when the Guatemalan cultural and environmental nongovernmental organization Fundación Patrimonio Cultural y Natural Maya, or PACUNM, contracted with NCALM to map the region in 2016.
But previous explorations had found only pieces of the puzzle. “Archaeologists were working on the ground in the summers, kilometer by kilometer,” said NCALM Director Ramesh Shrestha. “If the work had continued in the classical archaeological method, they would not have finished in their lifetimes.”
LiDAR provided a fast and far more comprehensive view.
Airborne LiDAR is a remote sensing technology used to produce high resolution three-dimensional maps using lasers. It works by firing hundreds of thousands of laser pulses per second from an aircraft flying at a relatively low altitude; a timing device measures the round-trip travel time, using that information to create detailed topographical maps.
It is used in a variety of applications, including archaeology, charting land erosion, mapping the sea floor and identifying levees in danger of failing. NCALM provides research-quality data for a variety of governments, agencies, scientists and private users.
The work in Guatemala wasn’t NCALM’s first archaeological survey; Bill Carter, chief research scientist and co-principal investigator for the center, said the center has provided archaeological data for about 20 other areas in Mexico and Central America since 2009.
“Little by little, we are putting together a picture of how the Americas were populated before the arrival of the Europeans, before Columbus,” said Juan Fernandez-Diaz, senior researcher with the center.
The Guatemalan project was the largest archaeological LiDAR project ever – covering about 2,100 square kilometers, or 811 square miles, more than one and a half times the surface area of the city of Los Angeles.
For the Guatemala project, the LiDAR information was gathered over the course of eight days and 44 hours of flight and involved 38 billion laser pulses. The plane was equipped with a state-of-the-art multispectral Titan MW LiDAR sensor, based on specifications requested by NCALM and developed by Teledyne Optech. It can emit up to 900,000 pulses per second.
Once the maps have been produced, NCALM researchers assist the archaeologists in interpreting the findings, including distinguishing between vegetation and other natural features and those that were built by humans, including ancient buildings, roads and agricultural systems. The Guatemalan project even showed evidence of water management systems used by the Maya, Carter said.
That interpretation, Shrestha said, “is the real magic.”
And he said there is more work to be done.
“How the Maya lived, how they interacted, what made their civilization disappear … there are more contributions to be made from LiDAR.”