To digitalize environments, multiple 3D scans have to be registered. After registration, the scene has to be globally consistent. A straightforward method for aligning several 3D scans is pairwise matching, i.e., the new scan is registered against the scan with the largest overlapping areas. The latter one is determined in a preprocessing step. Alternatively, in  an incremental matching method is introduced, i.e., the new scan is registered against a so-called metascan, which is the union of the previously acquired and registered scans. Each scan matching is limited in precision. Both methods accumulate the registration errors such that the registration of a large number of 3D scans leads to inconsistent scenes and to problems with the robot localization.