A case study in the analysis of patterns of aerial reconnaissance in a lowland area of southwest Scotland

Abstract

Analysis of aspects of an ongoing programme of aerial reconnaissance, looking for archaeological sites revealed as cropmarks, in a lowland part of southwest Scotland has identified biases in the survey. Areas of known potential tend to be targeted at the expense of less rewarding ground, contributing to an imbalance in the known distributions of sites created by regional variations in land-use patterns. A relationship between areas with a high density of sites, in a year of exceptional cropmark formation, and a high incidence of sites that have not been adequately recorded also can be identified. The ongoing assessment of survey data is a key factor in offsetting the impact of such biases in the longer term, recognizing the active role of survey methods in data creation and the importance of understanding the biases inherent in data.

Cropmarks in main field crops enable the identification of a wide spectrum of buried features on archaeological sites in Central Europe

“…Many new archaeological sites or individual features which had previously not been discovered were identified during those springs. The extraordinary creation of cropmarks in dry years was consistent with results from other European countries (Cowley, 2002;Kershaw, 2003;Hanson and Oltean, 2003;Challis et al, 2009). The highest density of archaeological features discovered on sandy and sandy-gravel river terraces was because people in prehistory preferred to live in close vicinity to water sources, as evidenced by permanent archaeological investigations (see Gojda, 2004;Kuna, 2007).…”

Reconstructing the archaeological landscape of Southern Dobrogea: integrating imagery

“…The fact that sites can be easily missed has been clearly demonstrated by a consideration of sites recorded only on the periphery of photographs focused on other targets. 3 Indeed, it is a commonplace that more is often visible on photographs than was appreciated at the time by the photographer, as might reasonable be expected given the greater time to peruse every detail and the facility to enhance visibility by manipulating the image. Finally, accurate mapping of low altitude oblique photographs can be problematic in areas without suitable control points.…”

Are We There Yet? A Review and Assessment of Archaeological Passive Airborne Optical Imaging Approaches in the Light of Landscape Archaeology

“…To counteract any of these obvious geographical biases, several scholars have already questioned this particular reconnaissance strategy over the past two decades. Although flying higher and/or with a shorter focal length can draw more of the landscape into the photograph and a second observer/photographer onboard might certainly increase the archaeological detection rate, several papers also pointed out the advantage of a geographical 'total coverage' or 'seamless' approach [114,[123][124][125][126][127][128][129]. Moreover, since photographs that result from such a blanket survey are much better suited for automated image processing workflows, they also mitigate the prevalent bias that is created by simply not using these aerial observations.…”