MOBILE MAPPING FOR CULTURAL HERITAGE: THE SURVEY OF THE COMPLEX OF ST. JOHN OF THE HERMITS IN PALERMO (ITALY)

During the 11th and 12th century, the Arab-Norman architectural style characterized the most beautiful and important Cultural Heritage buildings in Sicily, and especially in Palermo (Italy). The relevance of these monuments is highlighted by their inclusion in the UNESCO World Heritage Sites List in 2015. For many years, the University of Palermo has been studying and documenting several Arab-Norman cultural assets, and in particular, the complex of St. John of the Hermits in Palermo (Italy). A first detailed 3D survey of the main structures of this complex was carried out using a terrestrial laser scanner while the 3D survey of the entire complex was made using a Mobile Mapping System (MMS). The paper describes the workflow and the results of the mobile mapping survey undertaken with a Handheld Mobile Laser Scanner (HMLS) based on Simultaneous Localisation and Mapping (SLAM) technologies. The work allowed surveying the entire site with an extremely fast acquisition and obtaining the geometric information useful for historical architectural valuations. In addition, due to the characteristics of the site, the work enabled the assessment of the HMLS data processing testing different automatic algorithms for point cloud filtering.