PREVENT: survey by uav of the bell towers

The study of a bell tower requires a multidisciplinary approach, which is not available yet in the scientific literature. The main objective of the PREVENT project, Integrated procedure for assessing and improving the resilience of existing masonry bell Towers at territorial scale, is to set up a procedure comprising the academic disciplines of Drawing, Building physics and Structural engineering. It aims at providing a scientific methodology for the evaluation and conservation of bell towers, in order to enhance their fruition opportunities. Surveying a bell tower is not an immediate operation due to their height. Current metric surveying indirect methodology is based on the construction of numerical models. The geometric or mathematical models constitute the subsequent phase. The use of laser scanner may have disadvantages. The geometric model of the bell tower can be obtained through an aerial survey by a geo-referenced Unmanned Aerial Vehicle (drone) and subsequent photo-modelling technique. It was decided to carry out an indirect survey by using image-based techniques. An approach was carried out, with “airborne acquisitions” via ‘drone’ support. The aerial photographic data sets were acquired by means of flight planning, in free or scheduled mode, to guarantee the entire coverage and minimize noise. The research has been applied to the Neapolitan bell towers. The integration between the knowledge process and the applicative procedures could allow the development of a model available for various strategic objectives: a new method for structural assessment; a general method of analysis aimed at the preservation of an architecture; a final product, conceived to be used by local administrators; tourism enhancement.