Extrinsic Calibration of 3D LiDAR Using Sphere Targets and Differential-corrected GPS

This paper presents an extrinsic calibration approach for locating the exact pose of a 3D LiDAR sensor suitable for autonomous or mapping vehicles using sphere targets and multiple DGPS antennas. The method employs constrained RANSAC for robust sphere detection, least-squares fitting for precise center estimation, and an iterative point-to-point alignment using SVD for computing the pose transformations. Experimental validation using road lane markers demonstrates a mean positional accuracy of 3.6 cm, with a standard deviation of 1.3 cm and a maximum error of 7.1 cm. The methodology can achieve calibration either with single-scan data or by aggregating data across scans. These results confirm the method's effectiveness in improving spatial data accuracy for autonomous navigation, HD map generation, and multi-sensor fusion applications.