Aerial archaeology: Infrared drones

Skip to Navigation

Ezine

  • Published: Oct 1, 2017
  • Author: David Bradley
  • Channels: Infrared Spectroscopy
thumbnail image: Aerial archaeology: Infrared drones

Aerial views below the ground

(a) Color orthoimage of a survey area at the Enfield Shaker Village, New Hampshire, showing location of historic buildings indicated on a 1917 map; (b) magnetic gradiometry survey data; (c) raw thermal imagery collected with a radiometric thermal camera; and (d) thermal imagery processed to show only values present in the lawn. (Images by Jesse Casana, Austin Chad Hill and Elise Laugier)

Aerial thermal, infrared, imagery could transform archaeology according to researchers from Dartmouth College in Hanover, New Hampshire, USA.

Research published in the journal Advances in Archaeological Practice could act as a user manual for scientists hoping to use modern thermal cameras, commercial unmanned aircraft (quadcopters, drones and other craft), and photogrammetric software to carry out aerial studies of sites of scientific and historical interest.

Thermal infrared imaging has been used for many years to locate buried architecture and other cultural landscape elements. However, success in this field depends on many variables, such as the composition of the soil, the soil's moisture content and any plant cover. Moreover, old-school field walking allowed archaeologists to obtain data across just one hectare each day, making it a very long-winded approach. Aerial thermography opens up a whole new vista on a site, not only can it cut through the foliage but it can cover a lot of area in much less time.

Historical picture

With modern thermal imaging systems it is also possible to record full spectroscopic data or temperature data for every pixel of the image recorded. The precision with which small, inexpensive and easy to operate drones, can be flown using a smart phone or tablet computer makes the aerial thermographic data even more comprehensive and accessible. The researchers point out that mapping multiple aerial images together is now relatively straightforward using new photogrammetric software, which automatically aligns images and features ortho-image capabilities, to correct aberrations and make the scale uniform across images that may have been assimilated from different altitudes and attitudes.

Jesse Casana and colleagues tested their novel approach to aerial archaeology with case studies of six archaeological sites in North America, the Mediterranean, and the Middle East. They hoped to demonstrate just how effective the approach could be in carrying out aerial thermal surveys. They assessed how the weather, environment, time of day, ground cover, and archaeological features all affected the results they could obtain and compared their data with earlier research and historical images.

Shaker style

In one example, at an ancestral Pueblo settlement in Blue J, New Mexico, USA, the team was able to map detailed architectural plans of a dozen ancient house compounds. This particular discovery was facilitated by the site having good conditions, low density ground cover and perfect environmental conditions at the time of the aerial thermography. The study also revealed traces of long-gone buildings and pathways at the Shaker Village in Enfield, New Hampshire.

"A lot of what we’ve learned from our research to date shows how much local environmental conditions and the timing of surveys can impact how well thermal imagery will reveal archaeological remains," Casana explains. "Yet, the more we understand these issues, the better we are able to deploy the technology. I think our results demonstrate aerial thermography’s potential to transform how we explore archaeological landscapes in many parts of the world.

Related Links

Adv Archaeol Practice 2017, online: "Archaeological Aerial Thermography in Theory and Practice"

Article by David Bradley

The views represented in this article are solely those of the author and do not necessarily represent those of John Wiley and Sons, Ltd.

Follow us on Twitter!

Social Links

Share This Links

Bookmark and Share

Microsites

Suppliers Selection
Societies Selection

Banner Ad

Click here to see
all job opportunities

Copyright Information

Interested in separation science? Visit our sister site separationsNOW.com

Copyright © 2017 John Wiley & Sons, Inc. All Rights Reserved