Surveying and Mapping of Large-scale Topographic Map Based on UAV Image-free Control Point Technology

Using UVA image free point control technology for large scale topographic map can not only reduce the field workload, but also reduce the dependence on the aerial triangulation of office work, so it becomes a focus on current research. This paper deeply analyzes the technical principle of UAV image free control point, and deeply discusses the key technology of UAV image free control point during the mapping of large-scale topographic map. The practice of UAV aerial photography mapping 1:500 scale topographic map is carried out in Pu'an New District in Changchun city, an area in the urban and rural junction. By checking the accuracy of 1:500 scale digital line graph, it shows that the accuracy of 1:500 topographic map fully can meet the requirements of relevant specifications. It can provide reliable basic geographic information data for urban and rural planning in this area, and can confirm the feasibility and reliability of large scale topographic map with UAV image-free control point technology.