3D Modelling in the agora of Segesta: techniques and data interpretation

The aim of this paper is to illustrate the techniques used for data collection, elaboration and interpretation during the archaeological investigation in the agora of Segesta, conducted by the Laboratorio di Scienze dell’Antichità (LSA) of the Scuola Normale Superiore and the Laboratorio di Disegno e Restauro (LADIRE) of the Dipartimento di Civiltà e Forme del Sapere of Pisa University. The use of close-range photogrammetry, both terrestrial and aerial, combined with traditional drawing techniques, allowed us to improve the quality and amount of data collected for scientific purposes. As a result, the analysis of the archaeological stratigraphy, and especially the examination of structures and architectural elements, benefitted from a wider and more detailed collection of graphic data and information concerning the ancient site of Segesta. On the one hand, the use of terrestrial photogrammetric techniques, such as the so-called Structure from Motion (SfM), allowed us to obtain 3D models of the excavated area. At the same time, by using RPAS (Remotely Piloted Aircraft Systems) we started an up-to-date survey of the whole site. Using these new techniques, we were able to develop and improve the digital acquisition of data and create 3D models of the elements discovered and of the whole agora. Moreover,, thanks to the fundamental collaboration of the DreamsLab of the Scuola Normale Superiore, it was possible to achieve a virtual simulation of the public square of Segesta and of the most important buildings surrounding the agora. This virtual simulation of the agora in augmented reality, and the opportunity to visualize and utilize it within the Cave Automatic Virtual Environment (CAVE), will certainly make it possible to improve archaeological research and data dissemination, presentation and communication.