Kim, S.; Park, S.; Han, J.; Son, S.; Lee, S.; Han, K.; Kim, J., and Kim, J., 2019. Feasibility of UAV photogrammetry for coastal monitoring: A case study in Imlang Beach, South Korea. In: Jung, H.-S.; Lee, S.; Ryu, J.-H., and Cui, T. (eds.), Advances in Remote Sensing and Geoscience Information Systems of Coastal Environments. Journal of Coastal Research, Special Issue No. 90, pp. 386-392. Coconut Creek (Florida), ISSN 0749-0208.
This study assessed the potential of unmanned aerial vehicle (UAV) photogrammetry to accurately monitor coastal zone features, such as vertical profiles, and to detect shoreline. In total, 245 images with a ground spatial distance (GSD) of 1.59 cm were captured using a Zenmuse X7 camera mounted on an Inspire 2 UAV at Imlang Beach, Busan, Korea; 40 ground control points (GCPs) for UAV photogrammetry and 21 stations for terrestrial laser scanning (TLS) were surveyed using a network real-time kinematic (RTK) approach. The root mean square error (RMSE) values in the X, Y, and Z directions were 0.015, 0.017, and 0.040 m, respectively, based on bundle adjustment of 24 GCPs and 16 checkpoints. The root sum of squares error (RSSE) was 0.046 m. To assess the accuracy of the vertical profiles obtained for Imlang Beach, digital elevation models (DEMs) of six cross-shore profiles were constructed and compared based on UAV photogrammetry and TLS surveying. Vertical accuracy assessment showed an average difference in height between the models of 0.02 m and an RMSE of 0.04 m. A well-established object-based image segmentation approach was applied with standard parameters (size 100, shape 0.5, and compactness 0.5) to extract the shoreline from orthomosaic images of Imlang Beach. The results suggest that UAV photogrammetry has the capacity to achieve accurate and continuous coastal monitoring.