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標題: | 運用水下麥克風陣列之船舶偵測及定位研究 Study of Underwater Acoustic Detection and Localization of Ships Using Hydrophone Arrays |
作者: | 江維新 Wei-Shin Chiang |
指導教授: | 陳琪芳 Chi-Fang Chen |
關鍵字: | 水下麥克風陣列,波束成型,船舶噪音, Hydrophone Array,Beamforming,Shipping noise, |
出版年 : | 2023 |
學位: | 碩士 |
摘要: | 本研究利用由兩組雙聲道之水下麥克風系統收集之資料,麥克風陣列佈放於雲林新虎尾溪口附近,並利用波束成型估計出船舶噪音方位角連續變化,結合音傳損耗估計聲源距離,取得其移動軌跡並達到定位之目的。
由於兩組水下麥克風屬於不同系統,系統之間存在時間偏移,系統時間偏移將會嚴重影響定位結果,使用船舶噪音做為外部聲源,進行兩系統之時間校正,校正前兩系統時間偏移約為19秒,經過使用船舶噪音校正後可將兩系統時間偏移所短至0.05毫秒以內。 使用交通部航港局所提供的船舶自動識別系統(Automatic Identification System, AIS)獲取在分析時段內接近水下麥克風陣列船舶的詳細資訊,本研究定位結果根據AIS所提供之經緯度進行分析,並考量到GPS之誤差,在船舶距離陣列1422公尺時,最大誤差應介於107公尺與137尺之間。 本研究比較波束成型與到達時間差法對於方位角估計結果,在訊雜比較高時,兩者差異約在4度以內,在訊雜比較小時波束成型則有較良好的估計結果。根據船舶噪音與環境噪音頻譜圖和音傳損耗模擬結果,船舶在距離陣列20公里估計仍與環境噪音有5~10dB之差距,結合與麥克風陣列指向性,預計監測距離可達20公里。 This study analyzed data collected by two sets of dual-channel hydrophone systems. The hydrophone arrays were deployed near the mouth of Xinhuli River in Yunlin, and beamforming was used to estimate the continuous change in bearing angle of ship noise. By combining this information with the estimation of sound transmission loss and source distance, the trajectory of the moving ship was obtained, achieving the goal of localization. Due to the different systems of the two hydrophones, there exists a time offset between the systems. This time offset significantly affects the localization results. Using shipping noise as an external sound source, time synchronization is performed between the two systems. The initial time offset between the two systems is approximately 19 seconds. After time synchronization using shipping noise, the time offset is reduced to within 0.05 milliseconds. The Automatic Identification System (AIS) provided by the Maritime and Port Bureau is used to obtain detailed information about ships approaching the hydrophones array during the analysis period. The localization results of this study are based on the latitude and longitude provided by AIS and account for GPS errors. At a vessel distance of 1422 meters from the array, the maximum error should be between 107 meters and 137 meters. This study compares the results of beamforming and time difference of arrival methods for azimuthal angle estimation. When signal-to-noise ratios are relatively high, the difference between the two methods is within approximately 4 degrees. In cases of lower signal-to-noise ratios, beamforming demonstrates better estimation results. Based on the spectrum analysis of shipping noise and environmental noise, as well as sound propagation loss simulations, even at a distance of 20 kilometers from the array, there remains a 5 to 10 dB difference between shipping noise and environmental noise. Combining this with the hydrophone array's directivity, the monitoring range is projected to extend up to 20 kilometers. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/89955 |
DOI: | 10.6342/NTU202303537 |
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 |
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