First used by NOAA decades ago, lidar uses one or more lasers to send out short pulses which bounce back to it after hitting an obstacle. This can be anything. From clouds to leaves. NOAA used it to measure clouds. NASA used lidar systems during the Apollo 15 mission to map the surface of the moon.
More modern uses were on the Phoenix Mars Lander. It used a lidar device built by Teledyne Optech to bounce lasers off Mars atmosphere in 2008. The data from the Phoenix Mars lander showed snow falling in the Martian atmosphere.
Today, Teledyne Optech designed the lidar system on the OSIRIS-REx spacecraft. You might remember its launch in September. OSIRIS-REx’s primary mission is to gather a sample from the asteroid Bennu and shuttle it back to Earth. To do this, OSIRIS-REx needs to know where to land. That’s where lidar comes in.
Laser pulses will strike Bennu’s surface and return to the spacecraft. Engineers back on Earth will use the information gathered by these laser pulses to create a map of Bennu and select the best landing site.
Back on Earth, archaeologists use a version of Teledyne Optech’s lidar system to search for remnants of Earth’s past. In this case, an archaeological research team used an airborne lidar system to search the Beaver River area in Oklahoma. 10,500 years ago, groups of hunters assembled near the Beaver River to funnel herds of bison into narrow gullies cut into the hillside by the river. Here, the bison were killed. The meat sliced off, and the piles of bones left behind.
Meg Watters, a specialist in remote sensing and 3D imaging for archaeology, explains what lidar can and can’t do. “You’ll never find bison bones with airborne lidar, but you can find the geological features that suggest a place to look.”
Teledyne Optech’s most impressive feature is dubbed “bare-earth.” It strips away the grass and trees and shows what lies beneath. Lee Bement, the archaeologist leading research in the Beaver River area, says the tech has “been useful in delineating where we need to concentrate our efforts. It saved us a lot of time and effort.”
Here’s a pair of images showing how powerful the “bare-earth” feature is.
The first one shows your average aerial photograph taken above a forest in Connecticut.
Here’s the same area using a bare-earth lidar image.
You can see the remains of stone walls, abandoned roads and more.
The same technology has been used to discover the remains of a ruined city in Honduras.
Lidar can’t replace getting your hands dirty. But it gives archaeologists another tool in studying our past. Just by narrowing the search, it gives today’s archaeologists a huge advantage.
Lidar imaging is just one example of the technologies developed by NASA finding uses in the private sector. Each year, NASA highlights dozens of technologies helping the private sector in their Spinoff publisher. Here’s the 2016 version.