Some like it hot: The impact of next generation FLIR Systems thermal cameras on archaeological thermography

Abstract

Infrared thermography, or thermal imaging, has been used as a remote sensing technique to determine whether subsurface features such as walls or pits generate a heat differentiation from the surrounding earth. To date, this form of remote sensing has been notoriously difficult to perform due to cost, low-resolution thermal cameras and an inability to provide a stable aerial photographic platform. Furthermore, thermal fluctuations produced by archaeological remains are highly volatile, and are dependent on a multitude of variables such as soil moisture, particle size, and the construction materials of features. These issues have restricted the use of infrared thermography within archaeology. Yet, with the rapid development and adoption of unmanned aerial vehicles (UAVs) over the last decade as well as developments in thermographic technology, thermal imaging is now affordable and can be attached with relative ease to a multitude of UAVs. This paper reviews a new, low-cost, FLIR Systems thermal camera made specifically for UAVs, which were successfully employed at the Ancient Methone Archaeological Project, Pieria, Greece. By utilizing the FLIR Vue Pro, along with a DJI Phantom 2, aerial thermography was performed at the site at a cost far below that proposed by previous studies, with results also equalling or exceeding those methodologies. In combination with high resolution aerial photogrammetry, this methodology has helped to clarify previous archaeological investigations at the site, as well as revealing significant rectilinear subsurface remains.