TL-GILNS: A Trajectory-Layer-Enhanced GNSS/INS/LiDAR Integrated Approach Toward Reliable Positioning and Accurate Accuracy Quantification

Multisensor integrated navigation, combining the global navigation satellite system (GNSS), inertial navigation system (INS), and light detection and ranging (LiDAR), is at the forefront of high-precision positioning technology. However, existing integration methods rely on raw point cloud data, which cannot be obtained in some projects due to geospatial data privacy concerns. For this problem, this work introduces the trajectory-layer-enhanced GNSS/INS/LiDAR integrated navigation system (TL-GILNS), which operates without raw point cloud data. This novel approach faces two primary challenges: 1) the difficulty in resolving the divergence of LiDAR positioning results due to cumulative errors and 2) the challenge of accurately assigning weights to LiDAR data in the integrated system. To overcome these obstacles, we propose a trajectory-layer LiDAR positioning enhancement method to reduce cumulative errors and a trajectory-layer LiDAR positioning accuracy quantification method to determine the weight of LiDAR. Finally, the performance of TL-GILNS is verified through experiments conducted in semi-open and large-scale complex scenes. In these scenes, TL-GILNS achieves horizontal accuracy better than 0.3 m, vertical accuracy better than 0.7 m, and yaw angle accuracy better than 1°. These results demonstrate the potential of TL-GILNS as a leading approach for high-precision navigation and positioning in complex environments.