近年來隨著水下無人載具的發展，將水下無人載具應用於各式水下作業，其中包含探勘及偵測，應用範圍涵蓋聲學定位、聲學監測與追蹤、無線資料傳輸等，最後可應用於軍事國防、科學研究、以及商業民生等範疇。水下無人載具在水下以聲學方式進行資料傳輸，然而聲波傳播特性受海洋環境條件影響，因此海洋環境變動對於水下無人載具之聲學成效將造成影響；再者，由於水下無人載具之操作深度經常橫跨表面聲道內外，因此聲學通道中，海洋表面聲道的存在與特性對聲學應用成效之影響將特別顯著。
本文欲研究表面聲道對於移動式聲源（水下無人載具）的聲學通道之影響，利用中央氣象局在宜蘭外海佈放的海底觀測站（MArine Cable Hosted Obserbatory, MACHO）為固定接收訊號中心，並以拖曳式聲源於淺水層持續發射訊號，量測淺水層水文環境下的聲學特性。另外以聲線法模式進行通道預估，探討表面聲道對於通道聲學參數：包括訊雜比、多路徑效應、都普勒效應的影響等。根據實驗資料與聲線法模式之分析結果發現，海洋表面聲道效應會顯著影響移動式聲源的聲學通道之訊雜比。此研究的結果可運用於移動式聲源的聲學儀器成效預估上。

In recent years, underwater vehicles are applied in many underwater operations, e.g. exploration, naval operation and detection, etc. While underwater vehicles are operated, acoustics play key role on localization, monitoring, and wireless data link. However, oceanic environment including dynamic water column, sediment type, and bathymetry affect acoustic propagation. This thesis focus on the effect of surface duct on sound propagation for mobile source. We conducted an experiment, and towed the acoustic source transmitting 5 kHz signals, received by bottom mounted hydrophone connected by marine cable hosted observatory of Central Weather Bureau. Ray theory is also adopted to explain the phenomena observed in experiment. Results show the signals to noise ratio and multiple path effect (arrival structure) are highly fluctuated by surface duct.

論文審定書 i
誌謝 ii
中文摘要 iii
Abstract iv
目錄 v
圖 次 vii
表 次 xi
Chapter 1 緒論 1
1.1 研究背景 1
1.2 研究目的及方法 3
1.3 文獻回顧 4
1.3.1 移動式聲源（載台）之聲學應用 4
1.3.2 表面聲道傳輸（Surface Duct Propagation） 5
1.4 論文架構 8
Chapter 2 海上聲學實驗 9
2.1 實驗地點及過程 9
2.2 實驗配置與儀器介紹 14
2.3 實驗聲源訊號 19
Chapter 3 實驗資料分析 21
3.1 訊雜比（Signal to Noise Ratio） 21
3.2 脈衝壓縮（Pulse Compression）處理 23
3.2.1 解調/調變 23
3.2.2 低通濾波 26
3.2.3 相關性積分 27
3.3 都普勒效應 28
3.4 均方根壓及聲壓位準 29
3.5 通道能量變化 30
3.5.1 2012年實驗之通道響應 30
3.5.2 2013年實驗之通道響應 31
3.6 接收能量分析 34
3.6.1 2012年實驗之接收能量分析 34
3.6.2 2013年實驗之接收能量分析 35
3.7 實驗資料討論 38
Chapter 4 數值模擬分析 43
4.1 聲學模組BELLHOP 43
4.2 模擬環境設定 46
4.3 音傳損耗模擬 50
4.4 載台深度變化之影響 53
4.5 歷年水文資料模擬 56
Chapter 5 討論與結論 60
5.1 討論與結論 60
5.2 建議 62
參考文獻 63

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