Data Fusion in Archaeological Survey: Integrating Drone-Based Thermal and Multispectral Imaging with Established Techniques

Current practices in archaeological survey are well established and consist of both ground-based and remote sensing techniques. However, whilst passive remote sensing techniques employed within this field have traditionally been limited to the use of conventional RGB and grayscale photography to capture the traces of archaeological features from the air, recent years have seen a series of investigations into the suitability of applying multispectral and thermal imaging techniques to detect wavelengths beyond the visible portion of the electromagnetic (EM) spectrum for the same purpose. Preceding studies in this area of investigation have largely addressed the question of how best such techniques may be applied independently to draw out traces of subsurface archaeology, often placing an emphasis on the application of vegetation indices (VIs) to multispectral data. This paper adopts a novel approach, shifting the focus of research to examine how these emerging techniques may most appropriately be used alongside better-established and more widely practiced archaeological survey methods. To this end, the research assesses both a range of datasets gathered through conventional means as well as multispectral and thermal imagery covering the same survey area, before applying image sharpening data fusion techniques to produce composite imagery combining features from multiple datasets. To the researcher’s knowledge, this study represents the first use of such techniques for this purpose. The paper demonstrates through both visual and statistical analysis that these methods hold significant potential to aid the archaeological interpretation of buried sites by enhancing contrasts between different archaeological and non-archaeological characteristics of an observed landscape. In doing so, it builds on previous research by illustrating the most effective ways to merge datasets obtained through both established and emerging archaeological survey methods to create rich composite imagery.