UAVs Photogrammetry for Inner Areas Documentation.

Italy’s small historic centers in inland regions face significant fragility due to administrative challenges, depopulation, and geomorphological risks that threaten their long-term stability. As part of the EU-funded Next Generation EU PRIN 2022 project, this research initiates an experimental action aimed at developing a replicable methodological protocol for the rapid and integrated digital documentation of the historic center of Stigliano (Matera, Basilicata). The objective is to generate a detailed, reality-based 3D model of the urban fabric—encompassing both buildings and open spaces—to serve as the foundation for a digital information system dedicated to the preservation and enhancement of the site. The initial phase of the project focuses on data acquisition through photogrammetric techniques using mini-UAVs combined with mobile laser-scanning systems. This integrated approach, particularly well-suited for sites at high conservation risk, provides speed, flexibility, and comprehensive data capture. The challenging morphology of Stigliano, characterized by substantial elevation differences, a dense and irregular urban layout, and numerous narrow, inaccessible pathways, required a carefully structured close-range acquisition strategy. Additional terrestrial laser-scanning technologies, both static and mobile, were used to fill remaining data gaps. This paper presents the first results of the drone-based survey campaigns and discusses the methodological challenges encountered, along with the subdivision strategies adopted to produce a high-resolution 3D model of the historic center.