Improvement of Lidar Data Accuracy Using Lidar-Specific Ground Targets

Abstract

With recent advances of lidar technology, the accuracy potential of lidar data has significantly improved. State-of-the-art lidar systems can achieve 2 to 3 cm ranging accuracy under ideal conditions, which is the accuracy level required by engineering scale mapping. However, this is also the accuracy range that cannot be realized by routine navigation-based direct sensor platform orientation. Furthermore, lidar systems are highly integrated multi-sensor systems, and the various components, as well as their spatial relationships, introduce different errors that can degrade the lidar data accuracy. Even after careful system calibration, including individual sensor calibration and sensors intra-calibration, certain errors in the collected data can still be present. These errors are usually dominated by navigation errors and cannot be totally eliminated without introducing absolute control information into the lidar data. Therefore, to support applications that require extremely high, engineering scale mapping accuracy, such as transportation corridor mapping, we propose the use of lidar-specific ground targets. Simulations were performed to determine the most advantageous lidar target design and targets were fabricated based upon the simulation results. To investigate the potential of using control targets for lidar data refinement, test flights were carried out with different flight parameters and target distributions. This paper provides a description of the optimal lidar target design, the target identification algorithm, and a detailed performance analysis, including the investigation of the achievable lidar data accuracy improvement using lidar-specific ground control targets in the case of various target distributions and flight parameters.