Aerial and ground-based surveying and 3D modeling of cultural heritage – a case study in Messolonghi, Western Greece

Digital twins of cultural heritage are urgently needed for both comprehensive documentation and digitalization of the monuments, and, also, for the efficient planning of restoration activities towards increased resilience to climatic stressors. Here, we present a workflow for geodetic field surveying followed by 3D building information modeling (BIM), to create a digital twin of an example historical building of Western Greece, the ‘Old Hatzikosta Hospital’ in Messolonghi. More specifically, a detailed point cloud was generated, based on data collected with a Terrestrial Laser Scanner. Building features not directly detectable from the ground (e.g., rooftops) were mapped with photogrammetry using an Unmanned Aerial Vehicle (UAV). The collected data were then further analysed to derive a detailed 3D model of the monument. This 3D model could serve as a baseline for future engineering applications, such as planning maintenance and restoration interventions. Moreover, the digitalization of cultural heritage could also assist in raising public’s awareness and making such historical buildings more widely visible and accessible (e.g., virtual tours, interactive geodatabases etc.).