Articles by Jacopo Bonetto

This paper describes the high-resolution survey of the archaeological site of Nora (Sardinia, Italy) using the aerophotogrammetric technique. The survey was conducted in October 2021 on a 14-hectare peninsula located in the Gulf of Cagliari. Previous attempts to survey the area, aside from the 1 metre/pixel LiDAR survey carried out by the Region of Sardinia, have been hampered by the challenges posed by the size of the area and the costs involved. The Digital Terrain Model was obtained from the 3D model created with the Agisoft Metashape© software by removing the buildings and the vegetation. The segmentation process was carried out using Cloud Compare and the resulting DTM was then analysed using the geomorphological analysis tools provided by QGIS. The seabed DTM was obtained through several survey campaigns between 2013 and 2015, using the same software. The terrestrial DTM was merged with the seabed DTM, resulting in a comprehensive 3D and 2D model of the peninsula and its surroundings. The final DTM was printed with rapid prototyping technologies to explore its potential use as a tactile model for promotion and dissemination in the field.

The ancient city of Nora was a Phoenician, Punic and Roman settlement rising on a peninsula in the south-western coast of Sardinia. Since 1990, the University of Padova has been carrying on an interdisciplinary research project of excavation, architectural analysis, historical reconstruction and cultural promotion of tourism in this site. The excavations allow us to increase our knowledge of Middle Imperial Roman urban planning and to get a better understanding of the whole city and its history; the restoration of excavated monuments using gravels with different colours helps more than 60,000 tourists every year to recognize the function of different areas. In spite of this, visitors experience difficulty in understanding a landscape of ruins with barely visible evidence. Thus, a complete virtual reconstruction of the ancient city has become essential. 3D models of the Phoenician and Roman settlement have been developed, reshaping archaeological plans produced in 25 years by Universities that work in the site. The main monuments of the Roman city and the major crossroads have been rendered in greater detail, using sample-based textures that give a photorealistic effect and implementing the models with furniture and decorations selected through reliable sources of information. 3D reconstructions are now available for tourist groups led by a guide in the Nora Virtual Tour: stereoscopic images have been rendered and uploaded in an app for mobile headsets that provides immersive virtual reality for the users. The guide controls the devices with a tablet using a Bluetooth connection: at the beginning of the visit, the tourists can view equirectangular panoramas of the ruins taken from a helicopter, then they are accompanied to hot-spots where the ancient monuments are shown in an evocative Roman reconstruction.

Due to the recommencing of methodical archaeological excavation on the site of Nora, first Phoenician then Punic and Roman town, situated on the southern coast of Sardinia approximately 30 Km west of Cagliari, it was necessary to establish a cartographic system extended to all the hill on which the settlement standed (the settlement had never been completely mapped). This system had to cover previously surveyed areas and to allow the continuous updating with data resulting from new excavations. With these requirements, a computerised cartographic system was created, which consisted of basic information regarding not only the archaeological remains, but also the modern topography and the morphology of the hill. The aim was to design an operating system practical both for research and for safeguarding the archaeological site and allowing planning of its infrastructure. The project has been carried out in several phases: a) planning of the cartographical base; b) aerial survey of the zone; c) aerophotogrammetric zone; d) implementation of the numerical cartographic system; e) layout of the archives. The aerophotogrammetric information produced numerical files containing 3D data for every mapped point; using this data it was possible to create 3D models whose use is not only for archaeological research but also for aiding in planning for future infrastructural intervention in the archaeological park.