Empirical Evaluation of Terrestrial Laser Scanner Calibration Strategies: Manufacturer-Based, Target-Based and Keypoint-Based

To assure accurate terrestrial laser scanner (TLS) point clouds, the instruments should be repeatedly calibrated in the manufacturer’s facilities, either in regular time intervals or if they fail the examination on a test-field. This workflow has drawbacks for the end-users: there is no deeper understanding of the calibration procedure and it is time- and money-wise burdening. As an alternative, scientists developed several user-oriented calibration approaches, which are not well accepted in practice. We investigated the differences between the factory calibration and two user-oriented calibration approaches, as well as their interaction. The investigation focuses on the raw point clouds without factory calibration. Our results show that the user-oriented calibration can replace the manufacturer calibration to some degree. However, the user-oriented calibration on top of the manufacturers’ calibration improves the measurement quality beyond the factory calibration. Hence, user-oriented calibration should be considered as an alternative for the re-calibration to deliver up-to-date calibration parameters.