HIGH RESOLUTION DATA FROM LASER SCANNING AND DIGITAL PHOTOGRAMMETRY TERRESTRIAL METHODOLOGIES. TEST SITE: AN ARCHITECTURAL SURFACE

Terrestrial methodologies, as high resolution laser scanning and digital photogrammetry, are used in many applications in the field of architectural and cultural heritage surveys: they are characterized by different operative procedures and precisions. Data deriving from acquisition of an architectural surface, “morphologically complex” but geometrically simple and regular, were used in order to compare different methodologies. The 3D laser scanning data were acquired with HDS2500 Time Of Flight (TOF) terrestrial laser scanner and Konica Minolta Vivid 910 triangulation laser scanner. Moreover, the application of traditional topography with Leica TC2003 total station provided the 3D coordinates of 70 natural points, placed in the survey area, with high accuracy. The photogrammetric survey was performed with Canon EOS 1 DS Mark II digital metric camera: with 3 m and 6 m camera-to-object distances, 13 images with 10 cm and 20 cm, respectively of base increment, were acquired. The overlap between subsequent images is 95%, but with non subsequent images it ranges from 40% to 95%. For each stereo-pair, a stereoscopic model was created with Socet Set v. 5.4 software and the corresponding digital model was extracted. The different models were co-registered in the same reference system using control points and, subsequently, were compared: results indicated a good agreement between the data derived from HDS2500 laser scanner, digital photogrammetry and natural points. Moreover, the applicability of Konica Minolta Vivid 910 laser scanner for detailed architectural survey was demonstrated.