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標題: | 海洋聲源偵測與定位研究 Study on the Detection and Localization of Underwater Sound Sources |
作者: | Chang-Chih Chen 陳昶志 |
指導教授: | 陳琪芳(Chi-Fang Chen) 陳琪芳(Chi-Fang Chen | chifang@ntu.edu.tw | ), |
關鍵字: | 被動式聲學監測,到達時間差定位法,陣列元素自我同步,中華白海豚,船舶噪聲, Passive acoustic monitoring,Time difference of arrivals,Array Element Self-Synchronization,Chinese White Dolphin,Shipping noise, |
出版年 : | 2022 |
學位: | 碩士 |
摘要: | 本研究分析放置於雲林新虎尾溪口附近之兩組雙聲道之水下錄音器音檔,其主要用於監測中華白海豚之鳴音,亦可用於分析航經船舶噪聲。透過NTU_PAM先篩選出鯨豚哨叫聲,或使用船舶噪聲音檔逕行短基線到達時間差定位,計算出方位角連續變化,結合水下音傳模擬計算之距離結果,探討其移動軌跡並達到定位目的。 由於兩組不同之水下錄音系統存在時間偏移,本研究為消除系統時間偏移,同時針對時間校正探討。以SM3M 水下麥克風為例,外界聲源如敲擊聲及船舶噪聲,校正前之偏移量約為每小時26 毫秒,經校正後其偏移量可精確至每小時30 微秒。證實經過適當校正可消除兩系統間之時間偏移,且此時間校正方法可應用於不同儀器間。 定位結果顯示,鯨豚在5 分鐘音訊紀錄中,游向變化為由西北方經由測點西側往西南方,且距離測點約100 至120 公尺。船舶偵測部分,其訊雜比最低至1.24 dB時仍可偵測船舶方位角變化,且可在較微弱訊號中排除多餘之雜訊。因此在與AIS相同時間資訊之情況下,並考量GPS 之定位誤差,船舶定位結果誤差範圍介於71.4 至 91.4公尺。 This study analyzes two sets of two-channel underwater sound recorders placed near the estuary of Xinhuwei Stream in Yunlin, which are mainly used to monitor the whistles of Chinese White Dolphins, and can also be used to analyze the noise of ships passing by. First screen out the whistles of dolphins via NTU_PAM, or use ship noise files via the short-baseline of Time Difference of Arrival for positioning, calculate the continuous change of bearing angle, and combine the distance results calculated by underwater acoustic transmission model to discuss its movement trajectory and achieve positioning purpose. Due to the time offset of the two different underwater recording systems, this study aims to eliminate the time offset of the system and investigate the time correction at the same time. Taking the SM3M underwater microphone as an example, the uncorrected offset of external sound sources such as percussion and ship noise is about 26 milliseconds per hour. After correction, the offset can be accurate to 30 microseconds per hour. It approves that the time offset between the two systems can be eliminated by proper correction, and the time correction method can be applied on any different instruments. The positioning result shows that in the 5 minutes sound recording, the swimming direction of dolphins was from the northwest through the west side of the measuring point to the southwest, and the distance from the measuring point was about 100 to 120 meters. And the ships detection shows, the change of the ship's bearing angle can still be detected when the signal-to-noise ratio was low to 1.24 dB, the unnecessary noise can also be eliminated in weaker signal. Therefore, under the same time data as AIS, and considering the positioning tolerance of GPS, the deviation of the ship positioning result is between 71.4 and 91.4 meters. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/86187 |
DOI: | 10.6342/NTU202201371 |
全文授權: | 同意授權(全球公開) |
電子全文公開日期: | 2022-09-06 |
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 | |
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U0001-0907202216374600.pdf | 11.43 MB | Adobe PDF | 檢視/開啟 |
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