Application Research On Digital Terrestrial Photogrammetry In Engineering Survey

In the process of railway surveying and design, the terrestrial close-range photogrammetry can be used in engineering and topographic mapping over some important construction sites. The new principle of multi-baseline and multi-image photogrammetry promoted the development of traditional close-range photogrammetry technology. The corresponding multi-baseline digital close-range photogrammetry system was successfully developed. The methods brought new application research opportunities to digital terrestrial photogrammetry in engineering surveying.The technology of multi-baseline close-range photogrammetry can break the limitation of traditional single-baseline photogrammetry. The method solved incompatible contradiction between intersection angle and image matching in traditional close-range photogrammetry. The aerial triangulation and adjustment algorithm were introduced into the system. Through discussion on the new theory of multi-baseline photogrammetry, this thesis analyzed the whole process and key technology of multi-baseline digital close-range photogrammetry system from photography, camera calibration, stationing scheme, data processing to stereo mapping. Using common digital SLR camera, the digital terrestrial photogrammetry system were applied in the surveying projects of Nanning to Guangzhou and Jinzhongnan railway with the rotating multi-baseline photography. The accuracy and efficiency of photogrammetric data were analyzed. We obtained the geometric information, physical information about the tested objects, and worksite topographic map which can meet the accuracy requirements through the DPW. The research results validated the feasibility and reliability of multi-baseline digital photogrammetry for high-efficiency and high-precision topographic mapping in railway surveying over important construction sites, cross or vertical section investigation, and3D reconstruction for important building structure.