Geometric analysis of the original stands of roman amphitheater in Tarragona: method and results

Abstract

Despite being a well-known monument, the Roman amphitheatre of Tarragona, which is included in theUNESCO World Heritage List, was only fully studied in the late 1980s. The study was therefore subject tothe archaeological research limitations and specific characteristics of that time, as can be seen in the qual-ity of the site’s planimetry. The general planimetry was basically available for relevant sections at a scaleof 1:100 with sufficient accuracy. However, according to current scientific parameters, this planimetryis clearly inadequate, and cannot be used rigorously to obtain comprehensive architectural knowledge.The technical limitations of the time, and the innate difficulties presented by the monument, meant thatonly a few sections were obtained, specifically two, with a low level of detail. This has led to misinterpre-tations, and consequently to dubious or erroneous conclusions. Therefore, the need for complete metricdocumentation is evident, as this will enable us to correctly analyse the monument. We have obtainedmetric documentation by carrying out a topographic survey using digital photogrammetry, which pro-vides us with more information than merely measurements. We can use the three-dimensional modelthat was generated to analyse the sections of the stands and draw conclusions about their geometry.