Abstract: This paper investigates the application of UAV LiDAR technology to the mapping of transmission line flat sections in view of the problems of large workload, high risk in the field, difficulty in measuring ground point elevations in vegetation-covered areas and difficulty in measuring cross-crossing conductors in traditional transmission line flat sections. Firstly, the principle and advantages of UAV LiDAR are analysed, and then key technologies such as UAV LiDAR field data acquisition, laser point cloud filtering to build DEM, 3D feature acquisition, elevation information extraction and rapid mapping of flat sections are studied in depth. The results show that the method can achieve high accuracy and intelligent mapping of flat sections, with a two-fold increase in efficiency, and provide technical support for transmission line path optimisation. It has great economic and social benefits, and is worthy of application and reference.

Key words: UAV LiDAR, transmission line, flat section map, point cloud filtering, 3D acquisition, section extraction