Abstract: UAV tilt photography technology is greatly affected by occlusion and is difficult to penetrate the densely vegetated area, this paper proposes a method to update the large-scale digital topographic map of a small area with the tilt model combined with LiDAR point cloud in the urban complex terrain environment. Firstly, the UAV of five lens and six rotor is used to take two full-scale photos of the experimental area in the direction of vertical and parallel to the main buildings, and the unmanned airborne laser radar collects the point cloud in the whole area, and carries out a single lens low altitude make-up flight for the villa area less than 10 m. After aerial triangulation, the inclined image point cloud and airborne laser point cloud are fused for modeling. Comparing three modeling schemes, the inclined 3D model of the fusion modeling is the best in position accuracy and model quality. Finally, the mapping is carried out based on this model. The accuracy evaluation shows that under the condition of reasonable flight scheme and image control point layout in the urban complex terrain environment, the plane and elevation accuracy of the 1:1000 digital topographic map collected by the inclined three-dimensional model fully meets and is better than the accuracy index of the dynamic update of the 1:1000 digital topographic map in Shenzhen.

Key words: tilt photography, LiDAR, point clouds, 3D model mapping, map updating