Airborne Lasers Create 3D Images of Ancient, Modern Landscapes

In places like Belize and Cambodia, dense jungle and underbrush make it difficult for archaeologist to map the remains of ancient civilizations. It can take decades to piece together an image of ancient foundations, roadways or other structures. But one technology primarily used by ecologists and biologists to analyze vegetation cuts through jungle growth and produces detailed, three-dimensional views of landscapes in a matter of hours.

The technology is called LiDAR, which stands for light detection and ranging. It works something like radar and sonar, but instead of using radio or sound waves, it uses light, or laser signals. It can be flown from onboard an airplane, which passes back and forth, lawnmower style, over the area to be mapped. The laser shines millions of pulses of light onto the landscape, some of which bounce off of trees, shrubs, grass, hills, and rocks, and then reflect back to a sensor on the plane. The minute differences in height of the vegetation -- down to about an inch -- change the time it takes the light to reflect back. That difference is recorded by the sensor and then a computer program turns it into an image.

"You can literally peel away the vegetation," said assistant professor of archaeology Sarah Parcak, director of the Laboratory for Global Health Observation at the University of Alabama and expert in remote sensing technology.

In this article from the New York Times, the husband and wife anthropological team of Arlen Chase and Diane Chase tell of their surprise of the many details revealed of Caracol, an ancient Mayan city in Belize (right). Look closely at the bottom corner of the image above and you'll see terraces.

But the technology is not just being used to map ancient cities. Modern ones are benefiting, too. In New York City, the Office of Long-Term Planning and Sustainability is employing LiDAR to "create up-to-date maps of the areas most prone to flooding, the buildings best suited for the installation of solar power and the neighborhoods most in need of trees." Currently, the maps available to city planners date to the 1980s. According to the New York Times article, the $450,000 effort is part of Mayor Michael Bloomberg’s environmental agenda, also known as PlaNYC. 

The price tag may be one hurdle for researchers, who don't have big-city budgets.

"It’s cost range is many of hundreds of dollars per square kilometer, around $700 to $900 a square kilometer," said Parcak.

But as the technology grows more popular, the price could come down and help reveal cities unseen for centuries.

WATCH VIDEO: Hurricane Damage Detailed By Light: LIDAR sheds light on destruction caused by Hurricane Rita.