Integrating LiDAR and Photogrammetric Data for 3D City Modelling in Port Harcourt

Three-dimensional city models provide the spatial data foundation for urban planning, disaster simulation, solar energy estimation, telecommunications network planning, and smart city applications. This study integrates airborne LiDAR and UAV photogrammetric data to produce a Level of Detail 2 three-dimensional city model for a 12-square-kilometre pilot area in the Port Harcourt Government Reserved Area and Old Port Harcourt Town. Point cloud data from a LiDAR survey conducted at a pulse density of eight points per square metre are processed through ground filtering, building segmentation, and roof reconstruction algorithms in TerraSolid and CityEngine software. Concurrently, UAV photogrammetric surveys generate high-resolution orthomosaics that are texture-mapped onto the reconstructed building models to produce visually realistic LOD2 representations. The combined dataset is stored in a CityGML-compliant spatial database. Accuracy assessment of building footprints against digitised reference polygons yields a mean position error below twenty centimetres. The resultant 3D city model is evaluated through structured user testing for urban planning, emergency services routing, and flood simulation applications in collaboration with the Rivers State Ministry of Physical Planning. The study demonstrates the feasibility and cost-effectiveness of integrated LiDAR-photogrammetric workflows for 3D urban data production in a major South South Nigerian city. Keywords: LiDAR, photogrammetry, 3D city model, Port Harcourt, urban modelling.