科研之友
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摘要
A small unmanned aerial vehicle (UAV) platform is becoming low-cost, miniaturized hyper spectral imaging technology. The direct measurements of wave induce current is tested using image analysis techniques using sea dye maker and small unmanned aerial vehicle (UAV). Specially, rip currents are approximately shore normal seaward flows which are strong, localized and rather narrow. In this method, UAS at a region with frequent wave induced current occurrence, and images are continuously obtained in real time.
This research investigates the development of wave induced currents using images in East coast of Korea. Since rip currents are developed by longshore currents, the observed longshore current variations in space and time can be used to detect rip current generation. Rip current recorded by UAV when the significant wave height was 1,9m and the period was 6.0sec. The average velocity was 25cm/s. These remote sensing observations provide a more synoptic picture of the rip current flow field and allow the identification of several rip events that were not captured by the in situ sensors and times of alongshore deflection of the rip flow outside the surf zone. This study was conducted as part of the preliminary research for developing a method that can precisely measure the trend and velocity of wave induced current using small unmanned aerial vehicle (UAV) - based on single photo-photogrammetry. Quantitative estimation of wave induced current is also conducted by using average and variance image of wave induced current area. These efforts will contribute to reduce the hazards of swimmers and shoreline changes by prediction and warning of rip current generation.
- 出版日期2018-5
