Investigating Laser Scanner Accuracy

In a research project, i3mainz has installed a number of different test targets that allow an investigation in the quality of measurements obtained with laser scanners. The standardized tests, carried out since 2003, also allow a comparison between instruments of different manufacturers for the first time. The test procedures include scans of plane surfaces of different reflectivity in different ranges to obtain information about the noise of the range measurements and about systematic offsets caused by different materials. Several test fields using white spheres as targets have been installed to get information about the accuracy of distances in scanning direction and across. Due to different angular increments and spot sizes, not all 3D scanners have the same abilities to resolve small object details. 3D scanners are also known to produce errors at edges. Both phenomena are tested with appropriate targets. The tests are still available and producers and users are invited to have their instruments examined.