LIDAR IMMS VS HANDHELD MULTICAMERA SYSTEM: A STRESS-TEST IN A MOUNTAIN TRAILPATH

Abstract. Indoor Mobile Mapping Systems (IMMS) are attracting growing attention, especially when LiDAR sensors are considered, thanks to the possibility to obtain wide range and complete data in those areas where GNSS signal is not available. However, the drift error that accumulates during the acquisition is often inadequate in the absence of quality constraints in case of extensive acquisitions. Concurrently, recent developments regarding multicamera mobile solutions have shown promising results in containing the drift error, but data produced are too noisy and not enough complete in terms of acquisition range. This paper compares a Laser Scanner IMMS and a multicamera system in a stress test concerning the survey of a complex and extended route. The two systems are the Laser Scanner Backpack IMMS Heron MS Twin Color produced by Gexcel and a laboratory prototype of a handheld photogrammetric multicamera named Ant3D. The objectives are to calculate and compare the drift errors and to evaluate the quality of the produced point clouds. Quantitative results demonstrate that the drift error per meter of trajectory for the Heron Backpack is 10 times greater than the one of the multicamera. From a qualitative aspect, Heron Backpack generates 3D data in a wider range, allowing a more complete reconstruction of the environment when compared to the multicamera system one. On the other hand, the encumbrance and manoeuvrability of Ant3D make it more versatile in surveying very narrow spaces.