Process of airborne lidar data for detection of complex overpass

Three-dimensional (3D) model data of overpasses are significant for traffic navigation, landscape design, and many other applications. In this study, we use airborne light detection and ranging (LiDAR) data for 3D reconstruction of complex overpass. We propose a new technical framework for 3D reconstruction of complex overpass, including point cloud extraction, connectivity-based segmentation, determination of structure units, occlusion detection and restoration, and 3D modeling. To reduce the technical difficulty, we propose a concept of “structure unit”. The general idea of this framework is to divide an entire overpass into many simple “structure units”, and then derive a complete 3D model by reconstructing each “structure unit”. The experiments provide specific analysis and evaluation from two aspects: correctness and completeness, horizontal accuracy.