Continuous coastal monitoring using UAV photogrammetry

摘要

The purpose of this study is to collect ortho-images and point clouds acquired from UAVs in February and May tocomprehensively assess whether they are suitable for time series offshore monitoring, such as volume change calculationand shoreline extraction. In February and May, UAV photogrammetry was performed at an altitude of 100 m usingZenmuse7 of Inspire-2 for the research area, and 245 chapters and 240 chapters were collected in ground sample resistance(GSD) 1.59 cm and 1.62 cm respectively. We obtained 40 and 21 ground control points (GCPs) that will be used for UAVphotogrammetry and TLS surveying by using RTK-GNSS. The collected UAV images were treated as Pix4D mappersoftware. As a result, we deployed each point cloud and ortho-images in February and May. Image processing showed thatthe root mean square error (RMSE) in February was 0.015, 0.017, 0.040 m (x, y, z), and in May was 0.018, 0.015, and0.035 (x, y, z).To verify accuracy, point clouds data collected with TLS surveying were collected. Using TLS point cloudsand UAV point clouds (Feb, May), each DEM was deployed and the volume was calculated. In addition, a physical crosssectionanalysis was performed using 2 lines at the deployed TLS DEM, UAV DEM (2, 5 month). Finally, the coastlinefor the Imlang beach was extracted by applying the object based image segmentation technique obtained from UAV.