SMU archaeologist brings history into focus with LiDAR and 3D tech

3D images of the Fort Anne site.

Dr. Jonathan Fowler is bringing Nova Scotia’s historic settlements into sharper focus, using advanced digital tools to combine archival maps with landscape data in his research and teaching at Saint Mary’s.

“This is about as close as you can get to time travel without a DeLorean,” says the associate professor of archaeology. Instead of going Back to the Future, the texture mapping technology offers a fresh approach to viewing the past, showing in stunning detail how our farmlands and fortresses looked hundreds of years ago.

In a current project, Fowler shows how Fort Anne National Historic Site would have looked in 1706, combining a centuries-old military map with a 3D terrain model created from current aerial Light Detection and Ranging (LiDAR) data. 

“Airborne LiDAR has become a powerful tool for archaeologists to tell the stories about our heritage while also providing historical information for us to study and interpret,” says Fowler, who teaches in the Department of Anthropology.  

LiDAR technology has been around for decades, but the provincial government’s open data model is enabling an explosion of new research in many disciplines. Free LiDAR data is now available for much of Nova Scotia through GeoNOVA’s DataLocator Elevation Explorer portal. Aircraft mounted with LiDAR transmitters and receivers fly over landscapes across the province, emitting pulses of light energy. This provides detailed data about the ground surface, and archaeologists can filter out trees and other high vegetation to see a bare surface model.

To process LiDAR data, Fowler’s go-to is the Surfer surface mapping platform from Golden Software of Golden, Colorado. He has been using it for years to visualize geophysical survey data, and more recently to collate and analyze LiDAR data with old maps. The technology “essentially drapes historical maps over digital 3D models, creating a vivid visualization of the former landscape,” he explains.  

For his Fort Anne images, Fowler used high-resolution scans of historic maps of the fortress: a 1706 military map from France’s National Archives, and a 1753 map from the Library of Congress, showing the site under British rule. He put them through a georeferencing process in a Geographical Information System (GIS) program, then used LiDAR data to create a ‘bare Earth’ 3D surface model of the area’s current topography, minus vegetation and buildings. Combining them in Surfer created a 3D map revealing the original layout of buildings within the fort’s ramparts and beyond.   

“Interestingly, most of the fort’s buildings no longer exist, but some structures still stand today in [the town of] Annapolis Royal and are among the oldest buildings in Canada,” says Fowler.

Fowler hopes to unearth new information about Fort Anne and its surroundings. As he has in Grand Pré and other projects, he can use the new 3D imagery as a guide to return with Ground Penetrating Radar to further investigate what remains hidden beneath the surface.

“Dr. Fowler’s research demonstrates the value of visualizing and modeling multiple diverse data sets to gain deeper scientific insights,” adds Blakelee Mills, CEO of Golden Software.

In another study of the Fortress of Louisbourg National Historic Site, Fowler used a map dating back to 1745, after the New England siege. Though Parks Canada rebuilt much of the town’s outer wall during the 20th century, LiDAR data shows evidence of the craters left when the British military attempted to demolish the site in the mid-1700s.

Aside from its research benefits, fun, and aesthetic value, this approach to historical mapping holds great potential for explaining landscape histories with vivid visualizations.

“Rather than asking someone to imagine a past environment, we can digitally render it in 3D, resulting in a much more immersive experience of the past,” says Fowler.

“As a teacher of history, archaeology, and heritage resource management and interpretation, I am thrilled that these tools are becoming more affordable and user friendly. We are presently integrating them into several of our archaeology courses, including Archaeological Remote Sensing, Landscape Archaeology, and Cultural Resource Management Archaeology.”

For more details on the Fort Anne project, read Dr. Fowler’s articles on LinkedIn and Facebook. Follow his updates on Twitter at @ArchInAcadie.