Debitage and Drones: Classifying and Characterising Neolithic Stone Tool Production in the Shetland Islands Using High Resolution Unmanned Aerial Vehicle Imagery

Abstract

Abstract:The application of high-resolution imagery from unmanned aerial vehicles (UAV) to classify the spatial extent and morphological character of ground and polished stone tool production at quarry sites in the Shetland Islands is explored in this paper. These sites are manifest as dense concentrations of felsite and artefacts clearly visible on the surface of the landscape. Supervised classification techniques are applied to map material extents in detail, while a topological analysis of surface rugosity derived from an image-based modelling (IBM) generated high-resolution elevation model is used to remotely assess the size and morphology of the material. While the approach is unable to directly characterize felsite as debitage, it successfully captured size and morphology, key indicators of archaeological activity. It is proposed that the classification of red, green and blue (RGB) imagery and rugosity analysis derived from IBM from UAV collected photographs can remotely provide data on stone quarrying processes and can act as an invaluable decision support tool for more detailed targeted field characterisation, especially on large sites where material is spread over wide areas. It is suggested that while often available, approaches like this are largely under-utilized, and there is considerable added value to be gained from a more in-depth study of UAV imagery and derived datasets.

Insular networks: An exploration of material distribution, insularity and island identity on the edge of Europe in the Shetland Neolithic

“…From this material blanks of different sizes were brought upslope for more formal roughing out. At the Beorgs of Uyea this pattern of staged mobility can also be seen with reduction largely occurring close to dykes and later stages identified further away (Cooney et al 2019;Megarry et al 2018).…”

“…Each of these tool types represents different strategies in the selection and procurement of raw material: where to get desirable material; how to approach quarrying; extraction; and working strategies. Unmanned aerial vehicle (UAV) and GNSS survey and excavations at Grut Wells and at the Beorgs of Uyea have provided detailed information about the quarrying and production process (Cooney et al 2019;Megarry et al 2018). Although these quarry sites are different in their topography and scales of quarrying, the process of extraction and initial reduction is broadly comparable.…”

The Digital Revolution to Come: Photogrammetry in Archaeological Practice

“…Although the production of accurate maps is essential to the field, some archaeologists have pointed out that, while photogrammetric data and models are being produced frequently, they have been analyzed less often (Megarry et al 2018). In the same study, Megarry and colleagues used models constructed from aerial photographs to evaluate Neolithic-era quarries.…”

UAS-Based Archaeological Remote Sensing: Review, Meta-Analysis and State-of-the-Art

“…Several studies exploited the DSM products for interpretative mapping of the archaeological features through PCA and artificial shading [61,63,72,79,88,89,96,97,100,101]. In UAS-based archaeogeography applications, the rectified images, ortho-mosaics and raster elevation images have been used in a great extent, and analyzed through classification and shape analysis techniques, to interpret the shape of historical structures [110], the distribution of historical [69] and traditional structures [78], buried remains [77,85], and archaeological artifacts [74,114,116].…”