請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/15510
標題: | 移動載具層析聲納系統之實現 Realization of a SONAR System for Moving Vehicles Tomography |
作者: | Scott David Yu 游文孝 |
指導教授: | 郭振華(Jen-Hwa Guo) |
共同指導教授: | 黃千芬(Chen-Fen Huang) |
關鍵字: | 移動聲層析,聲納系統,聲納方程式,水聲通道估測,都卜勒效應, moving ship tomography,SONAR system,SONAR equation,underwater acoustic channel estimation,Doppler effect, |
出版年 : | 2020 |
學位: | 碩士 |
摘要: | 本研究實現一套用於移動載具聲層析聲納系統,以及發展一套預 測該系統在淺海環境表現的模擬方法。 移動聲層析藉由量測節點之間 的精確走時差以反算海洋特性,包括溫度場、流場等。此系統發射都 卜勒敏感之聲學訊號,最大長度序列訊號以相位調變方式結合載波之 上,在接收端以匹配濾波器求得相關函數,並推算走時。 若將聲納系 統以移動載具拖曳可以增加測量聲線並且擴增遙測範圍。然而載具之 間的相對移動所產生的都卜勒效應會造成訊號在中心頻率以及波形上 的改變,此失真必須採用多重都卜勒匹配之演算法加以補償,才得以 在接收端維持足夠的訊雜比。 本文提出一套適用於移動載具聲層析的聲納系統,該系統由控制電 路、發射裝置、接收電路以及都卜勒訊號處理算法組成,詳述聲納系 統設計原則,並且發展出一套模擬方法,根據聲納方程式評估此系統 在複雜淺海水聲通道中的表現和訊雜比,並由該模擬方法合成接收端 所收到的聲學訊號,通過電路模擬軟體驗證該系統之性能。 最後,為 了驗證該聲學傳播模擬方法,於基隆望海巷灣實施海事實驗,由三艘 漁船各拖曳一組聲納系統,並沿著指定路線航行。實驗數據與模擬結 果在複雜的環境下仍呈現良好的一致性。 Moving vehicle tomography is a technique used to sense temperatures and currents in the ocean by measuring precise travel times of acoustic signals. This study presents the construction of a SONAR system for moving vehicle tomography and develops a method evaluating its performance in coastal water by underwater sound simulations. Signal phase-modulated by maximum- length sequence is transmitted by the transducer, and the received waveform is correlated with a replica of the transmitted signal to obtain the arrival pat- tern. Towing the transceivers by moving vehicles significantly increases the number of ray paths and thus improves the accuracy and coverage of monitor- ing. However, the motion-induced Doppler effect would lead to distortion in the signal. To compensate the distortion both in center frequency and wave- form, the technique of multi-Doppler match filtering should be applied. This study presents a constructed SONAR system for this application. The system is composed of a transmitter, receiver, control circuit, other peripheral modules and algorithm of multi-Doppler-match filtering. Also, this study develops a method based on SONAR equation to estimate the performance of the constructed system in the complex shallow water acoustic channel. This method uses several acoustic toolboxes to synthesize the received signal and passes it to circuit simulation tools for system verification. To validate the developed simulation procedures, a field experiment was carried out in WanHaiXiang Bay, Keelung, Taiwan on Sep.27, 2019, with three transceivers each towed by a moving ship. Comparison between the outputs of simulation and the results from the experiment is made with fair agreement in spite of complex environment. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/15510 |
DOI: | 10.6342/NTU202001460 |
全文授權: | 未授權 |
顯示於系所單位: | 工程科學及海洋工程學系 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
U0001-1307202009410800.pdf 目前未授權公開取用 | 20.42 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。