New digital technologies, as laser-scanning, represent a breakthrough innovation for restoration: the best practice offers details about geomatics-based process
The Municipality of Florence promoted a research to restore "Fortezza da Basso", one of the principal examples of 16th century military architecture in Italy.
A MoU was signed among the Municipality, the University of Florence (GeCo Lab), the Military Geographic Institute and the National Research Council (Institute for the Conservation and Valorization of Cultural Heritage).
GeCo Lab realised a virtual model. Photogrammetry and both ground and mobile scanning systems were used to survey the inside and the external perimeter: they generated over 3000 images and more than 530 scans to produce almost 17 billion point giving the position and size of every block of stone.
Scans were executed by means of Z+F IMAGER 5010C with integrated HDR-camera. A full-frame digital reflex camera, Nikon D700 was used for photogrammetry.
- Mobile Laser Scanning System by Microgeo, with a Riegl integrated with IMU, DMI and GNSS equipment.
- ProScan system by Leica Geosystems automatically registering thanks to tracking technology.
- Pegasus Backpack by Leica Geosystems, a wearable reality capture sensor platform, integrated with 2 Velodyne VLP-16, 5 cameras for RGB chromatic values as well as IMU and GNSS equipment.
- Zeb-Revo (GeoSLAM), a lightweight revolving laser-scanner, integrated with a Hokuyo UTM-30LX rangefinder.
A DJI Phantom drone was used for flight performance and ortho-photos were produced projecting a GSD of 11 meters.
The Municipality of Florence funded the research. 2 PhDs and 1 fellow student were required to set up and run the practice. Tools and equipment were provided by GeCo Lab and the Military Geographic Institute; mobile systems were provided by the above-mentioned companies which supported the research.
Evidence of success
We tested the effectiveness of workflow systems, both in terms of time and methods. The envisaged output (layouts, sections, façades, curtain walls) was produced in compliance with the deadlines and with the agreements signed by the Contracting parties.
One major difficulty encountered was the coordination of different types of work teams; besides, it was not easy to plan and carry out our work activities with respect to the calendar of trade fairs and exhibitions hosted by the Centre.
Potential for learning or transfer
This work is an integrated survey and the Fortezza is a training ground where new technologies can be researched and tested out to the benefit of cultural heritage. The value of the data acquired with this technology goes beyond the initial project intentions: it has the capacity to take the survey beyond its imagined scope as a metric device to also assume a cultural and therefore interpretative role.
The point model provides an archive of data that can be used in the future non only as interpretative documentation but also as role data, thanks to the increasing value of its density and accuracy. Although it was not generated for a specific objective, this data real value lies in the fact that it can be reused for additional purposes which were not imagined upon its acquisition. This can include providing new questions and opportunities and targeting new priorities from storage to analysis, interpretation and accessibility, to public presentation.
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