Recently, it is practical to adopt new surveying techniques such as UAV-SfM/MVS surveys. However, the accuracy and method of UAV-SfM/MVS surveys are unclear. The purpose of this study is to investigate the optimal surveys and analysis methods for UAV-SfM/MVS survey.
In the National Institute of Technology, Gifu College, aerial photos were taken in various conditions changing the camera angle, overlap rate, and sidelap rate using an UAV, and the survey was carried out using a GNSS and a total station. Three-dimensional (3D) models were created using Metashape, which was a software for constructing 3D models using SfM/MVS technology.
As a result, it was revealed that although the use of only vertical downward aerial photos ware inappropriate because of the formation of cavities in the 3D models, the modeling of the structure was improved by adding diagonal aerial photos. Consequently, the use of diagonal aerial photos are important to improve the distance accuracy and modeling of 3D models.
View full abstract