A self-calibration of the Leica Scan Station C10 scanner

Similar to other surveying instruments, the observed data from terrestrial laser scanner (TLS) can be impaired with errors. Then, calibration routine is necessary for the TLS to ensure the quality of the data and also to make it applicable for surveying applications. There are two calibration approaches available: 1) component, and 2) system calibration. Due to the requirement of special laboratories and tools to perform component calibration, then this approach cannot be implemented by most of the TLS users. In contrast, system calibration that can be performed through self-calibration is more convenient and the requirements (e.g. room with targets) are easier to be provided. Self-calibration bundle adjustment is carry out using measured spherical coordinates (e.g. distance, horizontal and vertical angles) as observations. In extension to the functional model of each observation, a set of calibration parameters was used, which were determined in a self-calibration procedure. These parameters are derived from well-known error sources of geodetic instruments as constant (a0), collimation axis (b0), trunnion axis (b1) and vertical circle index (c0) errors. Self-calibration was performed for Leica ScanStation C10 at laboratory with dimension 9m × 7m × 2.6m and 130 black and white targets were fairly distributed. Data obtained from seven scan station were processed and statistical analysis (e.g. t-test) has shown that only collimation axis (77.1 inch) and vertical circle index (-62.4 inch) errors are significant for the calibrated scanner