Scanning the underground: Comparison of the accuracies of SLAM and static laser scanners in a mine tunnel

• Workflow for complex testing of SLAM and static scanners in tunnels proposed. • Multiple static and SLAM scanners were tested in a rugged underground environment. • Comparable accuracy of static (overlap registration) and new-generation SLAM scanners. • SLAM scanners suffer from much greater noise, which can be easily reduced. • In a 120 m long curved tunnel, total RMSDs of 20 mm or better were achieved. Superior measurement speed is a great benefit of Simultaneous Localization and Mapping (SLAM) scanners, especially in enclosed spaces. Here, we (i) provided a workflow for testing both terrestrial static laser scanners and SLAM scanners in underground spaces, which can help to identify the partial components of the error, and (ii) using this workflow, we compared the performance of four SLAM and two terrestrial scanners in a mining environment (120 m long tunnel). Although SLAM scanners suffered from greater noise than static scanners, their performance was excellent, with root mean square deviations after primary georeferencing on control points within the range of 12–24 mm for SLAM and 22–27 mm for static scanners. This result, along with additional provided metrics, suggests that SLAM scanners of the new generation perform excellently in enclosed spaces which, along with their ease of use, makes them highly suitable for measurements in this type of environment.