下放式ADCP观测海流剖面的误差分析.pdf

第十屆水下技術研討會暨國科會成果發表會 2008年4月25 日．高雄市．國立中山大學 下放式 ADCP觀測海流剖面的誤差分析 1 2 3 4 邵煥傑 蘇蜂鈞 楊財銘 曾若玄 摘要 近十年來下放式聲學都卜勒海流剖面儀(Lowered ADCP)已經成為國際海洋學界上觀測整 層海流剖面分佈的一項重要儀器，本研究利用國內第一套 設備於 年 月、 月與 LADCP 2007 4 7 10 月觀測蘭嶼周邊的黑潮流場與 2008 年 3 月觀測宜蘭海域。資料分析處理的軟體式下載自美 國哥倫比亞大學 LEDO 所提出來的逆推法(inverse method) ，利用34 組觀測數據來比較儀器傾 角、下放速度與測量流速誤差值之間的相對關係，結果發現儀器下放速度若大於 1m/s 所計算出 來的誤差值就越大，誤差值接近 0.1m/s ，未來將調整下放速度來避免誤差過大的情形；此外並 討論 bottom track 和 non-bottom track 的觀測條件所呈現出來的差異性。 Error Analysis for Lowered ADCP Velocity Profiles Huan-Jie Shao Feng-Chun Su Cai-Ming Yan Ruo-Shan Tseng ABSTRACT In recent years, Lowered acoustic Doppler current profiler (LADCP) has become an important instrument for studying ocean dynamics because it can provide a wealth of useful top to bottom velocity profiles. In this study the first LADCP experiment in Taiwan was conducted on April, July and October in 2007 near Kuroshio Current around Lanyu island and on March 2008 near I-Lan coastal area. The LDEO LADCP software package developed by inverse method are used to process and analyze the velocity profile. By analyzing the field measurement the result showed that when the lowering-speed is higher than 1 m/s, the error will be larger. The result can be applied to improve the quality of velocity profile by LADCP. In this study, the variation of profile velocity calculated with bottom track and non-bottom track are also compared. 的海流資料，但是此方法不易獲得大範圍的觀測資 ㄧ