Testing 'Structure-from-Motion' photogrammetry for high-resolution topographic surveys in hydraulic laboratories

摘要

In experimental research, photogrammetric methods have been successfully used for high-resolution topographic surveys. This study discusses the performance of the fully automated photogrammetric method 'Structure from Motion' (SfM) for weakly-supported surfaces as well as for sediment surfaces. The results show that in our study seven images are sufficient to obtain a high-resolution SfM-DEM of a sand/gravel surface and that camera properties (such as resolution) are less important. In addition, we observe an accuracy improvement of the generated SfM-DEM for weakly-supported surfaces (e.g. smooth surfaces with low textures) by using additionally a structured illumination. However, a benefit from structured illumination is only observed for a single smooth surface with a homogeneous color while no benefits are observed for sand or gravel surfaces. Nevertheless, the accuracy of topographical measurements for sediment surfaces demonstrates the high potential of SfM for many applications in hydraulic laboratories.