Now you see me. An assessment of the visual recognition and control of individuals in archaeological landscapes

Visibility analysis has become extremely popular in landscape-oriented archaeology in recent decades and has become even more widespread with the popularization of GIS tools, which have multiplied the ways in which visual perception can be analysed and digitally modelled. Visibility has been used as a proxy for different archaeological approaches, from the analysis of subjective perception to the assessment of strategic control. While interest has most often been focused on how objects, features and sites are perceived, there has also been an interest in how visual control is exerted from archaeological sites or other places in the landscape. Within the latter approaches, the distances at which visual control can be exercised have usually been determined in a more or less arbitrary manner, without a clear and empirically informed reference on how things and, especially, people can be observed and recognized differently at a distance. In this paper, we present the results of a field experiment carried out to measure the distances at which individuals can be spotted, recognized and identified with the naked eye in favourable conditions. Based on these results, we introduce the concept of Individual Distance Viewshed (IDV) as a GIS-based representation of visual control. This will serve as a reference to better qualify potential visibility in landscape analysis. Finally, we illustrate the applicability of this approach with a case study which explores the relationship between visual control and mobility during the Iron Age in the NW of the Iberian Peninsula.