NSU professor shares aerial photo research | Environment

Dr. Tommy Hailey, an associate professor of anthropology in Northwestern State University’s Department of Criminal Justice, History and Social Sciences, reported findings from archaeological research he completed in Nebraska earlier this year in which he demonstrated how aerial photography can enhance archaeological research.

Hailey shared his expertise using digital and thermal images captured via aerial photography that could help researchers gather information on the Alkali Station, a post on the Oregon Trail in Keith County, Nebraska.

The Alkali images were taken during a workshop sponsored by the National Park Service on non-destructive investigative techniques.

Working near the Cedar Point Biological Station and Alkali Station site near Ogallala, Neb., Hailey piloted the NSU Cultural Resource Center’s powered parachute and shared operating procedures for photographing sites.

He demonstrated how to use low-altitude aerial reconnaissance flights to capture still and video digital images as well as thermal images that help researchers identify features ofarchaeological interest and document the site as it currently appears.

"When documenting a site for the first time, the NSU Cultural Resource Office’s standard operating procedure is to photograph the area from a distance and from multiple directions, followed by more intensive photography at closer range,” Hailey said. “The distance photographs allow the site to be seen in its current natural and cultural contexts and provide reference points for future researchers.”

Hailey shot oblique and near-vertical angle images from high altitudes of 1,000-1,200 feet as well as low-altitude obliques from 300-500 feet, depending on the characteristics of the site.  Photos were first examined in their original state, then processed using Adobe Photoshop software, he explained. Images are filtered to remove atmosphere haze, enhance color and make features more visible.

“Thermal imaging cameras record images beyond the range of human vision, at the far end of the infrared spectrum,” Hailey said. “Within these images, the outline of the rectangular remnants of the fort are quite distinct, as are the wagon ruts of the Old Oregon Trail and ruts going off in a northeasterly direction from the east side of the fort.”

The adjusted images also reveal details in the landscape that permit the identification of a number of cultural andnatural features of interest, such as wagon ruts, dry streambeds, the largerectangular part of the fort and depressions that could be the remnants of structures associated with the fort.   They also show the arrangement of what appear to be dividing walls within the fort and an apparent entrance on the south side. Many depict Oregon Trail ruts meandering through and around natural obstacles before disappearing beneath the convergence of modern roads and traces of what may be the remains of a settlement.

“These interpretations are purely speculative but other observations seem to lend credence to them, as least in my opinion.  They do seem to roughly match up with the historic plan of Fort Alkali,” Hailey said. “These observations may not be news to archaeologists familiar with the site, but if these features prove to be new discoveries and if they are associated with Fort Alkali, then the findings would be potentially be quite significant.”

The workshop was a unique opportunity for Hailey to share procedures for documenting a significant historical site by means of low-altitude aerial reconnaissance utilizing the NSU Cultural Resource Office powered parachute.  Over the course of three morning flights, digital photographs and video as well as thermal still images and video were captured.

“These images provide a record of the appearance of the site at the time of the workshop and will allow archaeologists studying the site to gain new perspectives,” Hailey said.  “The potential for aerial reconnaissance at Alkali has not been exhausted.  Thermal imaging and digital photography may yet reveal features associated with Alkali Station that may continue to enhance our understanding of the inhabitants of Alkali Station.