Self-calibration of the Trimble (mensi) Gs200 Terrestrial Laser Scanner

Terrestrial laser scanning (TLS) is a widely used technology for acquiring dense and accurate 3D information of a scene. The features and capabilities of modern TLS systems have opened the market to many new fields, such as earth science and the movie production industry. To ensure that the best quality data are captured with a TLS instrument the system needs to be free of systematic distortions. This can be accomplished through a TLS system calibration procedure by the manufacturer or through a selfcalibration procedure. This paper explores the signalized targets-based self-calibration methodology and investigates the systematic errors and precision of Trimble’s pulse-based hybrid-type laser scanner, the GS200. The instrument was calibrated twice independently in two different rooms to evaluate the stability and consistency of the systematic error parameters. Results from this research show a significant range finder offset for the given scanner and non-standard target combination. The GS200 also showed signs of systematic distortion in the vertical direction as a function of the horizontal direction, which was modelled appropriately as an empirical term. Through mathematical modelling the observed range, horizontal circle and vertical circle reading precision of the GS200 were improved in both calibrations. * Corresponding author.