Tidal Reduction Method Based on Temporal Tidal Time-Difference Variations |
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| Authors: | Ju Liu Jingyang Bao Wei Zhou Jun Xu Xianghong Zhao |
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| Institution: | 1. Department of Hydrography and Cartography, Dalian Naval Academy, Dalian, China;2. liuju9752@163.com;4. School of Geodesy and Geomatics, Wuhan University, Wuhan, China;5. The 91550 Troops, Dalian, China;6. National Marine Technology Center Zhangzhou Base Preparation Office, Beijing, China |
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| Abstract: | AbstractTechnical developments in the positioning and depth detection fields have allowed for vast improvements in sounding results, but the effects of tidal reduction (TR) yet merit improvement; today, TR is the main factor that limits bathymetry precision. It is crucial to determine tidal time difference (TTD) between tidal gauges to conduct effective TTD-based TR. The influence of temporal TTD variations is usually ignored, and the temporal observation window to determine TTD is generally freely selected. In this study, temporal TTD variations were analyzed under the tidal constituent merging theory. Daily and hourly TTDs were compared and utilized to reduce the TR error during time difference method operation. At-sea experiments were conducted to contrast the effects of daily versus hourly TTDs on TR; the results indicate that hourly TTD is more precise and thus better suited to TR. |
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| Keywords: | Derivative of water-level curve least-square fitting tidal reduction (TR) tidal time difference (TTD) time difference method |
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