A Multi-Sensor and Multi-Temporal Approach to 3D Documentation of Historic Gardens: A Case Study of Villa Burba, Italy

Abstract. Historic gardens represent living heritage systems in which spatial configuration evolves through the interaction among vegetation dynamics, environmental conditions, and ongoing management. However, current 3D documentation approaches often treat these landscapes as static entities, limiting their ability to capture and interpret temporal transformations. This study proposes a multi-sensor, multi-temporal approach for the systematic documentation and monitoring of historic gardens, integrating UAV photogrammetry and mobile laser scanning (MLS) to enhance spatial completeness and analytical reliability.Two survey campaigns conducted at Villa Burba (Italy) in 2023 and 2025 produced multi-temporal datasets acquired under different environmental conditions. Following multi-sensor integration and temporal harmonisation, point cloud comparison was performed using the Cloud-to-cloud (C2C) distances and Multiscale Model-to-Model Cloud Comparison (M3C2) methods to quantify spatial differences. The results demonstrate centimetre-level geometric consistency and improved ground coverage by integrating UAV and MLS data, ensuring reliable comparability between epochs. Based on this, spatial changes were identified, including variations in vegetation structure, tree-removal events, terrain modifications, and changes to the internal watercourse. These findings were validated against botanical surveys and maintenance records, confirming their consistency with documented management activities and environmental conditions. To support interpretation and accessibility, the multi-temporal datasets were further deployed in GIS and on the Cesium platform using 3D Tiles, enabling interactive exploration and long-term data use. This proposed approach demonstrates how integrating photogrammetry with complementary surveying techniques can support multi-temporal analysis, contributing to more informed monitoring and interpretation of historic gardens as evolving landscapes.