Abstract: In the field of environmental protection and natural resource survey applications, this paper combines the external data collection of oblique aerial photography and measurement using UAVs in the experimental area. It aims at issues such as large elevation differences and weak textures in mountainous areas and complex buildings, and designs specifically for these challenges. By increasing the diversity of flight scales, the paper uses an optimized SFM＿MVS algorithm to jointly process multi-scale data, which compensates for a series of problems that ordinary consumer-grade cameras face in areas with large elevation differences. The construction of 3D realistic models of mountains, forests, and ancient buildings in a key area of Guangzhou has been successfully completed, with the completeness of the model improved by about 30% compared to the results of traditional UAV photogrammetry flights. The flight design and joint processing methods presented in this paper provide a beneficial exploration for the collection of 3D realistic models and environmental resource surveys in complex areas.

Key words: oblique photogrammetry, realistic 3D model, joint solution, environmental survey, resources survey