Accuracy and block deformation analysis in automatic UAV and terrestrial photogrammetry – Lesson learnt –

The paper reports the results of an integrated Unmanned Aerial Vehicle (UAV) and terrestrial photogrammetric survey realized in the archaeological site of the Roman theatre in Ventimiglia, Italy. The main deliverables were 2D drawings at scale 1:20, which required a Ground Sample Distance (GSD) less than 4 mm and, consequently, accuracy better than 4 mm. The UAV was employed to acquire both vertical and oblique images, while the terrestrial imaging acquisition was realized with the aim of generating separate dense point clouds of some vertical structures, corresponding to the sections required. The variability of results with automatic photogrammetric procedures against different image network configurations, with and without ground control, are analysed and presented.