High-Efficiency Determination of Coastline by Combination of Tidal Level and Coastal Zone DEM from UAV Tilt Photogrammetry

Chao Huang,Jianhu Zhao,Hongmei Zhang

doi:10.3390/rs12142189

Abstract

To meet the needs of coastline efficient extraction and dynamic monitoring, this paper proposes a new method for coastline extraction by combining the tidal level and the digital elevation model (DEM) of the coastal zone from tilt photography. Firstly, the DEM of coastal zone was obtained by using unmanned aerial vehicle (UAV) tilt photography; at the same time, the accuracy of aerial triangulation(AT) is improved referencing to the constraint of water boundary points, and then the mean high water spring tide was obtained by combining tidal harmonic analysis and Global Navigation Satellite System (GNSS) tidal level. Finally, the coastline and the dynamic water-surface line are extracted from the DEM of the coastal zone by tracking the contour lines with the elevation of the mean high water springs (MHWS) and the instantaneous sea-surface elevation, respectively. The experiments carried out in the coastal zones of Liaoning Province, China, proved the proposed method and achieved better than 0.2 m of horizontal position accuracy and 0.1 m of the vertical accuracy.

Highlights

The coastline is the boundary line between sea and land for dividing marine area and terrestrial administrative area [1]
The unmanned aerial vehicle (UAV) tilt photogrammetry is relatively infrequently used for coastal monitoring currently [22,23,24,25,26,27,28,29,30,31], it does provide a new high-efficiency and low-cost way to get the digital elevation model (DEM) of the coastal zone for the determination of the coastline, as well as richer terrain and texture information compared with traditional vertical photogrammetry
To efficiently get high-accuracy coastline, this paper proposes a new method by combining the tide information and the coast zone DEM from UAV tilt photography

Summary

Introduction

The coastline is the boundary line between sea and land for dividing marine area and terrestrial administrative area [1]. The field investigation method requires surveyors to arrive at the field and judge the positions of coastlines based on the trace lines formed by the erosions of high tide level on coastal zones, which is time-consuming, laborious, and various due to different manual experiences [9]. The UAV tilt photogrammetry is relatively infrequently used for coastal monitoring currently [22,23,24,25,26,27,28,29,30,31], it does provide a new high-efficiency and low-cost way to get the DEM of the coastal zone for the determination of the coastline, as well as richer terrain and texture information compared with traditional vertical photogrammetry

Methods

Results

Discussion

Conclusion