Retrospective Photogrammetry in Greek Archaeology

Abstract

This paper addresses the advantages as well as the obstacles in practicing photogrammetry based on archival photos of archaeological sites and examines how the results can be put to use for further research, preservation, restoration and monitoring rates of deterioration. While the extensive use of historic aerial photographs has been applied to photogrammetric modeling, archaeological excavation archives have been largely ignored. Historically, archaeological excavations have been vigorosly documented photographically and many of these photographs are available in archives. Not all photo archives, however, are suitable for photogrammetry, as they were not produced with the intention of overlap and other photogrammetric qualities. By selectively choosing photographs with common points and manipulating exposures, cropping and other properties to enhance commonality, 3D models of past structures and excavations can allow us to revisit them, produce accurate measurements and view angles that were never photographed. Employing this methodology for sites that are still accessible provides the opportunity for quantitative comparison of the current condition of the site to the condition at the time of excavation. Used in this way, retrospective photogrammetry will have impacts in the preservation, restoration and monitoring of the deterioration of archaeological sites. Examples from the Athenian Agora: the State Prison and Omega House, and Ancient Corinth: the Fountain of the Lamps will be used to demonstrate these possibilities.

Interregional Archaeology in the Age of Big Data: Building Online Collaborative Platforms for Virtual Survey in the Andes

“…The decreasing cost and wider availability of both declassified historic satellite photographs and high-resolution multi-spectral satellite imagery have begun to allow us to identify thousands of new archaeological sites at large scales -in some cases in areas spanning tens or even hundreds of thousands of square kilometers (Casana 2014;Parcak 2009;Parcak 2019;Ur 2003Ur , 2006Ur , 2010. Advances in photogrammetric tools and techniques enable processing of large historical aerial survey collections, enabling the production of high resolution 3D models, orthomosaics, and digital elevation models over large areas, which in turn enables detection and analysis of archaeological features that have since been destroyed or that have degraded considerably since the aerial photographs were taken (Wallace 2017).…”

Bridging Digital Approaches and Legacy in Archaeology

“…On most occasions, these data transformations are made with a view to enhancement, reanalysis or re-interpretation using novel IT tools and methods. Such aspects include studies in the grey literature [8], excavation datasets [9][10][11][12][13], survey and CRM records [14][15][16][17][18][19], archival material [20], retrospective photogrammetry [21,22], and data harvesting and modelling [23,24].…”

The Digital Revolution to Come: Photogrammetry in Archaeological Practice

“…Revisiting archival sources, archaeologists are beginning to demonstrate the value of old excavation photographs for contextualizing contemporary excavations in 3D. From case studies in Greece, Wallace (2017) demonstrated how using photographs from as far back as the 1970s to generate models provides a useful baseline for conducting archaeological work today. The use of old photographs was also productive for Paleolithic excavations, which often revisit the same sites and benefit from improved spatial context derived from archival photographs (Discamps et al 2016).…”