Evaluation of UAS Flight Configuration Factors and Their Impacts on Photogrammetric Survey Accuracy

Recent advances in computer vision and camera-equipped unmanned aerial systems (UASs) for 3D modeling enabled UAS-based surveys with high spatial-temporal resolutions. Although there have been many studies on various factors that affect the accuracy of UAS-based photogrammetry-based geospatial data, there is little to no quantitative method that identifies the relationships between flight configuration factors and point cloud accuracy. This paper seeks to assess the degrees of influences that these factors affect accuracy. This study assesses five impact factors using the ANOVA method to understand which factors have higher or lower impacts on the accuracy. The influence factors include flight height, average image quality, image overlap, ground control point (GCP) quantities, and focal lengths of cameras. The results show that the number of GCPs has the largest impact on the vertical and horizontal accuracies than other impact factors. The findings of this study can help surveyors better design flight configurations given different site conditions and constraints.