Optical 3-D Measurement Techniques VIII, Gruen/Kahmen (Eds.), Zurich, July 9-12, 2007, Vol. I, pp. 389-397. COMPARISON OF TERRESTRIAL LASER SCANNING SYSTEMS IN INDUSTRIAL AS-BUILT-DOCUMENTATION APPLICATIONS Harald Sternberg, Thomas P. Kersten HafenCity University Hamburg, Department Geomatics Hebebrandstrasse 1, 22297 Hamburg, Germany Email: [harald.sternberg, thomas.kersten]@hcu-hamburg.de Abstract: In this paper investigations into the practical performance of a complete terrestrial la- ser scanning system, consisting of scanner hardware and its related software for data processing, are described and compared for different laser scanners. To facilitate this, two projects were con- ducted to test four and two different laser scanning systems, respectively, in two different indus- trial as-built-documentation applications (transformer station and water conduits of a waste water treatment plant). In conjunction with the project workflow, the important aspects of preci- sion/accuracy and efficiency of both projects are discussed in this paper. 1. Introduction Terrestrial laser scanners are frequently used for various applications, which have different re- quirements for hardware and subsequent data processing via software. The spectrum of products required ranges from simple visualisation of objects using just point clouds, to approximation of objects in simple 3D models via detailed 2D facade plans and complex deformation measure- ments. On one hand terrestrial laser scanners should be tested from the instrumental point of view using investigations to check whether the instruments meet the accuracy specifications given by their manufacturers. Previous comprehensive investigations of laser scanning systems refer fre- quently only to the hardware components as presented in [2] and in [5]. On the other hand the overall system performance of a laser scanning system should be tested in comparison with other laser scanning systems, in order to see, if the system fulfils the user requirements for specific applications. The first investigations of the HafenCity University in terrestrial laser scanning for as-built-documentation of an industrial application are described in [6], while their first compari- son tests of Trimble GS100 and IMAGER 5003 scanners for an indoor cultural heritage applica- tion are summarised in [3]. Therefore, to invest more into the practical performance of an overall system, consisting of scan- ner hardware and its related software for data processing, two projects were conducted to test four and two different laser scanning systems, respectively, in two different industrial as-built- documentation applications (transformer station and water conduits of a waste water treatment plant). The investigations of the two projects are focused on scanning speed and scanning behav- iour, control point signalisation, precision/accuracy aspects, level of detail in the scans, and the efficiency of the work- and dataflow from scanning to 3D object modelling.