Improving Real-Scene 3D Model Quality of Unmanned Aerial Vehicle Oblique-Photogrammetry with a Ground Camera

Abstract

In UAV (unmanned aerial vehicle) oblique photogrammetry, the occlusion of ground objects, particularly at their base, often results in low-quality real-scene 3D models. To address this issue, we propose a method to enhance model quality by integrating ground-based camera images. This innovative image acquisition method allows the rephotographing of areas in the 3D model that exhibit poor quality. Three critical parameters for reshooting are the reshooting distance and the front- and side-overlap ratios of reshooting images. The proposed method for improving 3D model quality focuses on point accuracy, dimensional accuracy, texture details, and the triangular mesh structure. Validated by a case study involving a complex building, this method demonstrates that integrating ground camera photos significantly improves the overall quality of the 3D model. The findings show that optimal settings for reshooting include a distance (in meter units) of 1.5–1.6 times the camera’s focal length (in millimeter units), a front overlap ratio of 30%, and a side overlap ratio of 20%. Furthermore, we conclude that an overlap rate of 20–30% in reshooting is a usable value.

Keywords

• oblique photogrammetry
• ground camera
• reshooting parameters
• real-scene 3D modeling
• quality assessment