The survey of the external elevations and roofs of Duomo di Milano aimed to acquire a precise 3D dense point cloud and model to be used both for the projection of the orthophotos and for the 2D and 3D final restitution.
The survey was carried out using mainly the photogrammetry technique to obtain a high definition texture needed for the orthomosaic and also for mapping precisely some additional information like decay detection and restoration surgery information.
Several camera systems and lenses were employed to obtain a complete survey of each architectonical elements, maintaining the resolution approximately the same, therefore the GSD was kept suitable for the 1:50 representation scale. The different 3D reconstruction projects were then put together in a common local coordinates system using topography and GCPs.
