(Dipartimento di Architettura, DIDA UNIFI, Florence University , Italy, Florence, Italy)

Keywords: Photogrammetry, Structure from Motion, Maddalena ’s Bridge, Data comparison

How can we make the heritage built around us available through the new digital survey technologies?
The Maddalena bridge, in Borgo a Mozzano (LU) Italy, called “Devil’s Bridge”, is a monument of particular historical interest and it has been analyzed here with the aim to identify new way about how to use the data of a survey campaign through using different technological methodologies (laser-scan and photogrammetry) and new SFM software. The use of both data allows a greater knowledge of detail and better management of the survey campaign timing.
Some buildings, such as a bridge, located in particular topographical conditions may present some difficulties with survey ’s technologies. In this case, the water affected the normal return of the data through the laser scan; also the photogrammetric survey sessions obviously present physical barriers such as in our case the river, not navigable at the time of the survey campaign.
Therefore, the combined use of both laser-scan and the photogrammetric survey was indispensable in order to provide better detail accuracy. The new survey made in 2018 and its graphic restitution of Maddalena ’s Bridge, wants to offer itself as a usable basis to benefit from a comparison with a previous survey carried out in 2006, allowing us to analyze and compare the status of the current fact with the previous one and thus allowing to hypothesize possible consolidation and redevelopment interventions if necessary.
It was thus possible to highlight the changes offered by the new technological solutions that we now have available (the evolution of the Laser-scan, optical devices and cameras, software and digital components) that allow us to implement the knowledge of the survey.
Thanks to the survey itself, it was possible to create a 3D digital model available for complete use of the monument for tourism purposes.