Survey in Closed Environments Through UAS Technology. Methodological Approaches to the Study and Image Processing of Religious Furnishings

The present study deals with survey in closed environments with UAS technology and with the solutions of problems related to the adoption of innovative approaches for the investigation and knowledge of historical Cultural Heritage. In particular, the altar dedicated to St. Ignatius of Loyola in the Church of Collegio dei Gesuiti in Siracusa has been surveyed. Designed around 1756 by the sculptors Domenico Battaglia and Giovan Battista Marino, it is placed in the transept of the church and with its imposing presence it is the emblem of the great Baroque season in Sicily. The survey campaign developed two levels of analysis: on the one hand, the UAS experimentation for the image processing and on the other, TLS implementation for the collection of metric data. The integration of the two approaches leads to the creation of a detailed 3D model. More specifically, the low cost UAS platform used in the present experimentation lacking a GPS system can fly at a maximum altitude of 5 m. Therefore, given the great height of the architectural work, the main problem for the achievement of objectives was to find a solution to overcome such limits. This is fundamentally important in order to provide a large amount of information able to increase the collected data with the traditional systems of terrestrial surveying. Thus, the point cloud obtained from such an integration can be converted into a continuous high-resolution model, a higher density point cloud which can be a useful support for any further determination.