面向光聲海底地形探測的聲學(xué)信號建模與處理技術(shù)
發(fā)布時間：2018-12-09 11:59
【摘要】：海洋遙感是利用傳感技術(shù)手段對海洋進(jìn)行遠(yuǎn)距離非接觸觀測,以獲取海洋景觀和海洋要素的圖像或數(shù)據(jù)資料,達(dá)到海洋環(huán)境監(jiān)測、近海海洋勘察、海底地形探測、海洋動力現(xiàn)象觀測等重要目的。目前廣泛使用的海底地形測量系統(tǒng)有單波束回波測深儀、多波束回波測深儀以及機載激光測深儀。這些設(shè)備有各自的特點,也受制于各自的適用條件。 光聲探測概念的提出旨在突破傳統(tǒng)光學(xué)水深測量和傳統(tǒng)聲學(xué)水深測量的限制。激光作用于水體介質(zhì),在水體中激發(fā)聲波,形成激光聲源。利用基于水面聲光耦合原理的光纖水聽器作為海底回波的接收設(shè)備。將聲納的分辨率、距離優(yōu)勢與機載平臺的速度和機動性結(jié)合起來,在若干應(yīng)用場合可以作為傳統(tǒng)地形測量的一個重要補充。 本論文針對光聲海底地形探測中的聲學(xué)信號建模與處理技術(shù)進(jìn)行研究。光聲海底地形探測使用了新型探測聲源和新型信號接收方式,帶來便捷的同時也帶來了若干新的問題。本論文對激光聲脈沖的特性及海底回波模型,海底回波達(dá)到時間估計和動態(tài)水面環(huán)境下聲信號接收干擾消除等問題進(jìn)行研究。 主動聲納探測體系中,發(fā)射信號的特性是主動聲納探測研究中至關(guān)重要的一部分。論文從實驗采集到的激光聲脈沖數(shù)據(jù)出發(fā),對激光聲脈沖信號的特性進(jìn)行研究。在此基礎(chǔ)上,結(jié)合激光聲脈沖的特性、傳播衰減特性、海底散射等因素,建立了一種激光聲脈沖的海底回波模型,并通過仿真實驗驗證了模型的合理性。 光聲海底地形測量問題屬于含有未知參量的信號檢測問題,處理的信號為海底的后向散射回波信號。論文使用特征函數(shù)相關(guān)檢測的方法估計回波到達(dá)時間,此方法中特征函數(shù)為仿真產(chǎn)生的海底后向散射信號的包絡(luò)序列,特征函數(shù)相關(guān)檢測法利用了回波信號的幅度以及包絡(luò)的綜合特征,對海底回波的時間展寬和海底的隨機起伏具有較好的擬合能力。通過仿真實驗驗證了特征函數(shù)相關(guān)檢測算法的有效性和抗干擾能力。 論文最后從信號接收的角度,對基于水面聲光耦合原理探測水下聲信號的實驗進(jìn)行了重點研究,分析波浪可能對探測造成的干擾。在貝葉斯信號處理框架下,設(shè)計了一種基于時變AR模型的卡爾曼濾波器跟蹤并抑制波浪干擾信號。通過對實驗數(shù)據(jù)的濾波處理,驗證了所設(shè)計濾波器較之于傳統(tǒng)帶通濾波方法的性能提升。
[Abstract]:Ocean remote sensing is the use of sensing technology to conduct remote non-contact observation of the ocean, in order to obtain images or data of ocean landscape and ocean elements, to achieve marine environmental monitoring, offshore marine exploration, seabed topography detection, Ocean dynamic phenomena observation and other important purposes. At present, there are single beam echo sounder, multi-beam echo sounder and airborne laser sounder. These equipments have their own characteristics, but also subject to their own applicable conditions. The concept of photoacoustic detection is proposed to break through the limitations of traditional optical bathymetry and acoustic bathymetry. The laser acting on the water medium excites the sound wave in the water body and forms the laser sound source. A fiber-optic hydrophone based on acousto-optic coupling principle is used to receive underwater echo. Combining sonar resolution and range advantage with the speed and maneuverability of airborne platform, it can be used as an important supplement to traditional topographic survey in several applications. In this paper, acoustic signal modeling and processing techniques in photoacoustic sea bottom topography detection are studied. The photoacoustic sea bottom topography detection uses the new detection sound source and the new signal reception method, which not only brings convenience but also brings some new problems. In this paper, the characteristics of laser acoustic pulse, the model of underwater echo, the time estimation of underwater echo and the elimination of acoustic signal receiving interference in dynamic water environment are studied. In the system of active sonar detection, the characteristics of transmitted signals are very important in the research of active sonar detection. Based on the experimental data of laser acoustic pulse, the characteristics of laser acoustic pulse signal are studied in this paper. On this basis, a submarine echo model of laser acoustic pulse is established, which is based on the characteristics of laser acoustic pulse, propagation attenuation characteristic, undersea scattering and so on, and the rationality of the model is verified by simulation experiments. The problem of photoacoustic sea bottom topography measurement belongs to the signal detection problem with unknown parameters, and the signal processed is the backscattering echo signal of the sea floor. In this paper, the method of feature function correlation detection is used to estimate the time of arrival of echo. In this method, the characteristic function is the envelope sequence of the backscattering signal generated by simulation. The characteristic function correlation method makes use of the amplitude of echo signal and the comprehensive feature of envelope, and has a good fitting ability for the time broadening of sea bottom echo and the random fluctuation of seabed. The effectiveness and anti-interference ability of the feature function correlation detection algorithm are verified by simulation experiments. In the end of this paper, the underwater acoustic signal detection based on the principle of acousto-optic coupling on water surface is studied in detail from the point of view of signal receiving, and the possible interference caused by wave is analyzed. In the framework of Bayesian signal processing, a Kalman filter based on time-varying AR model is designed to track and suppress wave interference signals. The performance of the designed filter is improved compared with the traditional bandpass filter by filtering the experimental data.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN912.3
[Abstract]:Ocean remote sensing is the use of sensing technology to conduct remote non-contact observation of the ocean, in order to obtain images or data of ocean landscape and ocean elements, to achieve marine environmental monitoring, offshore marine exploration, seabed topography detection, Ocean dynamic phenomena observation and other important purposes. At present, there are single beam echo sounder, multi-beam echo sounder and airborne laser sounder. These equipments have their own characteristics, but also subject to their own applicable conditions. The concept of photoacoustic detection is proposed to break through the limitations of traditional optical bathymetry and acoustic bathymetry. The laser acting on the water medium excites the sound wave in the water body and forms the laser sound source. A fiber-optic hydrophone based on acousto-optic coupling principle is used to receive underwater echo. Combining sonar resolution and range advantage with the speed and maneuverability of airborne platform, it can be used as an important supplement to traditional topographic survey in several applications. In this paper, acoustic signal modeling and processing techniques in photoacoustic sea bottom topography detection are studied. The photoacoustic sea bottom topography detection uses the new detection sound source and the new signal reception method, which not only brings convenience but also brings some new problems. In this paper, the characteristics of laser acoustic pulse, the model of underwater echo, the time estimation of underwater echo and the elimination of acoustic signal receiving interference in dynamic water environment are studied. In the system of active sonar detection, the characteristics of transmitted signals are very important in the research of active sonar detection. Based on the experimental data of laser acoustic pulse, the characteristics of laser acoustic pulse signal are studied in this paper. On this basis, a submarine echo model of laser acoustic pulse is established, which is based on the characteristics of laser acoustic pulse, propagation attenuation characteristic, undersea scattering and so on, and the rationality of the model is verified by simulation experiments. The problem of photoacoustic sea bottom topography measurement belongs to the signal detection problem with unknown parameters, and the signal processed is the backscattering echo signal of the sea floor. In this paper, the method of feature function correlation detection is used to estimate the time of arrival of echo. In this method, the characteristic function is the envelope sequence of the backscattering signal generated by simulation. The characteristic function correlation method makes use of the amplitude of echo signal and the comprehensive feature of envelope, and has a good fitting ability for the time broadening of sea bottom echo and the random fluctuation of seabed. The effectiveness and anti-interference ability of the feature function correlation detection algorithm are verified by simulation experiments. In the end of this paper, the underwater acoustic signal detection based on the principle of acousto-optic coupling on water surface is studied in detail from the point of view of signal receiving, and the possible interference caused by wave is analyzed. In the framework of Bayesian signal processing, a Kalman filter based on time-varying AR model is designed to track and suppress wave interference signals. The performance of the designed filter is improved compared with the traditional bandpass filter by filtering the experimental data.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN912.3
【參考文獻(xiàn)】
相關(guān)期刊論文 前7條
1 郭熙業(yè);蘇紹t，
本文編號：2369334
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