Benedetta ADEMBRI | Luca CIPRIANI | Filippo FANTINI | Silvia BERTACCHI
(Soprintendenza per i Beni Archeologici del Lazio, Alma mater Studiorum Università di Bologna, Italy)
Keywords: UAV, Hadrian’s Villa, digital photogrammetry, terrestrial laser scanner, data integration
Abstract:
Italian regulations about UAV provide a very strict and severe set of rules, especially in archaeological areas due to visitors’ safety and possible damage to the historic buildings. When the documentation of domes and cupolas – that is to say elevation structures – is necessary, alternative to UAV become essential. The case study of Serapeum at Hadrian’s Villa provides a good example: the presence of a high dome in good state of conservation and a narrow corridor with two water supply passages at the top of the structure make the flight very dangerous both for the devices and above all for keeping intact the state of the masonry walls. During the last surveying campaign carried out on this exemplary architecture, a set of different devices has been tested: in particular the integration between terrestrial laser scanner (phase-shift technology) and a passive sensor applied on the top of a telescopic stick made of carbon that can be extended up to ten metres.
The synergy of these two methodologies allowed to obtain a reliable and balanced sampling, both in terms of geometrical resolution and texels of the 3D model: the whole intrados area and the final corridor were in fact completed, achieving the fundamental support for documentation as well as restoration and maintenance activities. These possibilities of combining two acquisition technologies without safety restrictions and prolonged authorisation times proved to be efficient for documenting both fragments and fallen parts of the dome, in order to gather information and suggest plausible virtual anastylosis.