Development of a High-Precision, Portable and Automated Mobile Laser Scanner for the Recording and Digitation of Texture and Micro-marks in Archaeological and Heritage Stone

Abstract

[Abstract] The use of laser tools to digitise cultural heritage items is becoming more widespread but is generally limited to manual systems that rely on the user's movement or expensive automated equipment that is designed to scan large items but is not always able to accurately measure or reproduce specific details of small size. In this paper we present the novel high-precision system PALLAS, which allows the automatic digitisation of three-dimensional detailed surfaces. The equipment has been built using a set of motors and linear axes, control electronics and a line laser scanner that can be moved along the XY working plane. It is battery-powered for ease of use in the field and uses a standard laptop to communicate via Wi-Fi network. Custom software has been developed to automatically calculate paths, control the movement and store the profiles generated by the scanner. The software can also be used to reconstruct the surface from the set of scanner profiles, allowing the XYZ coordinates of any point on the surface to be measured and to obtain areal roughness parameters to characterise the finish and texture of the stone surface. Preliminary results obtained from masons' marks, rock engravings and petroglyphs are presented.