碩士 / 國立成功大學 / 水利及海洋工程學系 / 107 / The images sequence provides information on the sea surface characteristics in the time and spatial domain. In this study, UAV had been used to capture the images sequence. An image analysis method based on the three-dimensional Fourier transform was also developed for obtain the sea surface current information which could be calculated iteratively by dropper shift from wavenumber-frequency spectrum. The influence factors and observation setting of the UAV, including the quantity and position of the ground control points, the coordinate accuracy, the flight altitude, the wind speed and light, were also tested. The results show that the position of the ground control points is more affected than the quantity. We recommended that the ground control points be evenly distributed around the land area. In addition, GPS position from mobile phone (iPhone XR) can meet the needs of the UAV for ocean current observation. This study also found that the observation results are not good under the conditions of wind speed greater than 8m/s or sun elevation angle too high. For verification and validation of sea surface current calculated from UAVs images, X-band radar and ADCP had been deploy and compare with. The results show that the UAV observation results are consistent with the radar, and the comparison with ADCP shows that the RMSE of the current speed is 0.0985 m/s and the direction error is 12.9º.
| Identifer | oai:union.ndltd.org:TW/107NCKU5083018 |
| Date | January 2019 |
| Creators | Cheng-CheLee, 李丞哲 |
| Contributors | Dong-Jiing Doong, 董東璟 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 58 |
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