Skip to content

Archeologists Use Laser Technology to Examine the Past at Hawai‘i Volcanoes National Park

August 21, 2014
Kealakomowaena house site

LiDAR scan of a rock wall that forms part of a house site in Kealakomowaena. NPS Photo.

 

A vertical band of green light scans across a field. It is almost invisible in the bright daylight as it passes over rocks and clumps of grass, flashing through the underbrush before running along a low dry-stacked wall and bounding 100 yards back to a crumbling tumulus silhouetted against the horizon.  An archeologist stands behind the origin of the light: a boxy, 30-pound grey machine mounted on a yellow tripod. He watches as it slowly rotates 360 degrees, and scans petroglyphs within Hawai‘i Volcanoes National Park – a UNESCO World Heritage Site.  This modest machine is a potent tool for cultural preservation, and it represents the most advanced hardware available in the field of laser scanning, or LiDAR (Light Detection and Ranging).

 

 

As its name suggests, LiDAR technology has some similarities to RADAR (Radio Detection and Ranging). The difference is that information collected by LiDAR is infinitely more detailed and accurate. Every surface the green light touches during its 360° mission becomes digitized as millions upon millions of distinct coordinates (each with an identity in three imensions) recreates an image that we can recognize with our own eyes – imagine a pointillist painting. This new LiDAR “painting” is a file that contains a virtual world we can travel through and explore at leisure.

LiDar in the field

Hawai‘i Volcanoes National Park archaeologist Dusten Robins uses LiDAR to document the Pu‘uloa Petroglyph Field. NPS Photo/Jadelyn Moniz-Nakamura

The Cultural Resources Management team at Hawai‘i Volcanoes National Park has been using LiDAR since 2010. Much of what we do involves creating detailed scans of archaeologically or historically significant features around the park. From these scans, we can view an area from any angle, including a bird’s-eye view. We can make detailed measurements and even produce very accurate conventional plans and elevation maps without physically being at the site. All of this data can be tied to our existing Geological Information Systems (GIS) database to provide a further dimension of insight and information.  LiDAR is valuable to us because it quickly produces images of an area that are very accurate and highly detailed. Perhaps the greatest value of  LiDAR is the open nature of the data and the flexibility of the software we use to manipulate it. In the future, we would like to build a database of virtual sites that can be used for purposes ranging from research and mapping to monitoring for minute physical changes that indicate site deterioration. We hope to use some scans to create interactive experiences where visitors in the park and visitors online can navigate sites normally inaccessible due to their fragility or their remoteness.  Recent advances in 3D printing have made it possible to recreate scale models of structures and replicas of museum objects that can be held and examined while preserving the real thing from degradation.

 

LiDAR Pu‘uloa Petroglyphs

Petroglyphs at Pu‘uloa scanned with lidar as part of a documentation project. NPS Photo

Petroglyphs revealed

Closeup of Pu‘uloa petroglyphs scanned with Reflectance Transformation Imaging technology by University of Florida. Courtesy AIST

As an emerging technology, new applications for LiDAR are appearing as quickly as they can be imagined, and the discoveries are astonishing, especially at other UNESCO World Heritage Sites across the globe.  At Angkor Wat, the massive ruined temple complex set in the jungles of Cambodia, researchers used aerial  LiDAR to collect data which helped them understand what was going on below the dense forest canopy surrounding the site. The new information led researchers to identify the complex as Mahendraparvata, an intricately planned ancient urban center that stretches a dozen square kilometers beyond where Angkor Wat was believed to end. The newly discovered area contains never-before-seen canal and highway systems that were revealed in detail by the scan. Conservators in Central Afghanistan are using LiDAR to scan the empty niches and stone rubble that remains after the Taliban’s 2001 destruction of the monumental Buddhas of Bamiyan.  Specialists will use the three dimensional files in their effort to reconstruct these lost pieces of world heritage. Meanwhile, ecologists in the Peruvian Amazon have created what they call the Carnegie Airborne Observatory.  By equipping a twin prop plane with LiDAR, a spectrometer and a high-definition camera, they survey over 100 square kilometers of forest every hour to create maps that define each individual tree by its species and health. Elsewhere, LiDAR has been applied in atmospheric particle monitoring, the sensors aboard Martian rovers, experimental driverless vehicles, and a Radiohead music video, to name just a few.

For now, the sky is the limit for LiDar– at least the first 300 meters or so of it!

 

Written by Jadelyn Moniz-Nakamura, Ph.D., Integrated Resources Manager and Archeologist at Hawai‘i Volcanoes National Park 

No comments yet

Leave a Reply

Fill in your details below or click an icon to log in:

Gravatar
WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 232,880 other followers

Build a website with WordPress.com
%d bloggers like this: