新型干涉型光纤水听器动态范围研究及在水下测量中的应用
发布时间：2019-04-19 10:07
【摘要】：随着海洋科学的发展,光纤水听器的应用领域越来越广。比起传统的光纤水听器,声光耦合干涉型光纤水听器可以在空中机载平台发射探测激光,在水面通过激光多普勒效应耦合水下声场信患,通过检测反射光信号遥感测量水下声场信号。声光耦合干涉型光纤水听器不仅灵敏度高,而且可以对危险海域进行非接触式探测,是一种非常有潜在应用价值的传感器；本论文首先介绍了光纤水听器发展历史和声光耦合型光纤水听器的应用；研究分析了一种基于7r/2相位调制的声光耦合干涉型光纤水听器,介绍利用这种调制方法获取两路正交信号的原理；详细介绍了两种常用的光纤水听器数字解调方法,微分交叉算法和反正切算法,分别分析这两种解调算法的动态范围上限以及动态范围受限原因,对比这两种解调算法的优缺点；提出了微分交叉相乘算法无畸变动态范围的概念,通过分析其解调原理发现其动态范围上限随采样频率线性增大；通过Matlab仿真,分析了信号幅度、频率和采样频率对这两种解调算法的影响；并研究了当待解调的两路信号处于非正交的状态时对两种解调算法的影响。搭建了基于PZT环的π/2相位调制干涉实验系统,对振动信号进行解调测试,实验结果证明该解调系统最小可检测相移量为2.4×10-5rad,系统的动态范围受信号频率和采样频率的影响,当信号频率从5kHz变化到1kHz,系统无畸变动态范围从87dB提高到102dB。搭建了声光耦合型干涉水听器实验系统进行水池实验,探测到了水下10m处铝板的反射声波信号。根据实验结果分析,声光耦合型干涉水听器可检测最大深度为36m。最后提出了一种利用激光声源和声光耦合干涉型光纤水听器阵列探测水下目标方位和尺寸的方法,分析其工作原理。介绍了使用的差分定位算法和解卷积算法分别来估算水下目标方位和尺寸的原理。最后对探测系统进行了数值仿真,验证了这种方法的可行性。
[Abstract]:With the development of marine science, the application field of fiber optic hydrophone is more and more extensive. Compared with the traditional fiber optic hydrophone, the acousto-optic coupled interferometric fiber optic hydrophone can launch and detect the laser on the airborne platform and coupling the underwater acoustic field signal through the laser Doppler effect on the surface of the water. The underwater acoustic field signal is measured by remote sensing by detecting the reflected light signal. The acousto-optic coupled interferometric fiber optic hydrophone is not only of high sensitivity, but also can be used for non-contact detection of dangerous sea areas. It is a kind of sensor with potential application value. Firstly, the development history of fiber optic hydrophone and the application of acousto-optic coupling fiber optic hydrophone are introduced. An acousto-optic coupling interferometric fiber optic hydrophone based on 7r/2 phase modulation is studied and analyzed. The principle of obtaining two orthogonal signals by this modulation method is introduced. In this paper, two digital demodulation methods of fiber optic hydrophone, differential crossover algorithm and anti-tangent algorithm, are introduced in detail. The upper limit of dynamic range and the reason of limitation of dynamic range of the two demodulation algorithms are analyzed respectively. The advantages and disadvantages of the two demodulation algorithms are compared. The concept of differential cross multiplication algorithm without distortion dynamic range is proposed. By analyzing the demodulation principle, it is found that the upper limit of the dynamic range increases linearly with the sampling frequency. Through Matlab simulation, the influence of signal amplitude, frequency and sampling frequency on these two demodulation algorithms is analyzed, and the influence of the two demodulation algorithms when the two signals to be demodulated are in non-orthogonal state is studied. A 蟺 / 2 phase modulation interference experiment system based on PZT loop is built and the vibration signal is demodulated. The experimental results show that the minimum detectable phase shift of the demodulation system is 2.4 脳 10 ~ (- 5) radd. The dynamic range of the system is affected by the signal frequency and sampling frequency. When the signal frequency changes from 5kHz to 1kHz, the distortion-free dynamic range of the system increases from 87dB to 102dB. An acousto-optic coupled interferometric hydrophone experiment system was set up to carry out the pool experiment, and the reflected acoustic signal of aluminum plate was detected at 10 m under water. According to the analysis of the experimental results, the maximum detection depth of an acousto-optic coupled interferometric hydrophone is 36m. Finally, a method of detecting the orientation and size of underwater targets by using laser source and acousto-optic coupled interferometric fiber-optic hydrophone array is presented, and its working principle is analyzed. The principle of using differential location algorithm and deconvolution algorithm to estimate the orientation and size of underwater target is introduced. Finally, the feasibility of this method is verified by numerical simulation of the detection system.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB565.1
本文编号：2460847
[Abstract]:With the development of marine science, the application field of fiber optic hydrophone is more and more extensive. Compared with the traditional fiber optic hydrophone, the acousto-optic coupled interferometric fiber optic hydrophone can launch and detect the laser on the airborne platform and coupling the underwater acoustic field signal through the laser Doppler effect on the surface of the water. The underwater acoustic field signal is measured by remote sensing by detecting the reflected light signal. The acousto-optic coupled interferometric fiber optic hydrophone is not only of high sensitivity, but also can be used for non-contact detection of dangerous sea areas. It is a kind of sensor with potential application value. Firstly, the development history of fiber optic hydrophone and the application of acousto-optic coupling fiber optic hydrophone are introduced. An acousto-optic coupling interferometric fiber optic hydrophone based on 7r/2 phase modulation is studied and analyzed. The principle of obtaining two orthogonal signals by this modulation method is introduced. In this paper, two digital demodulation methods of fiber optic hydrophone, differential crossover algorithm and anti-tangent algorithm, are introduced in detail. The upper limit of dynamic range and the reason of limitation of dynamic range of the two demodulation algorithms are analyzed respectively. The advantages and disadvantages of the two demodulation algorithms are compared. The concept of differential cross multiplication algorithm without distortion dynamic range is proposed. By analyzing the demodulation principle, it is found that the upper limit of the dynamic range increases linearly with the sampling frequency. Through Matlab simulation, the influence of signal amplitude, frequency and sampling frequency on these two demodulation algorithms is analyzed, and the influence of the two demodulation algorithms when the two signals to be demodulated are in non-orthogonal state is studied. A 蟺 / 2 phase modulation interference experiment system based on PZT loop is built and the vibration signal is demodulated. The experimental results show that the minimum detectable phase shift of the demodulation system is 2.4 脳 10 ~ (- 5) radd. The dynamic range of the system is affected by the signal frequency and sampling frequency. When the signal frequency changes from 5kHz to 1kHz, the distortion-free dynamic range of the system increases from 87dB to 102dB. An acousto-optic coupled interferometric hydrophone experiment system was set up to carry out the pool experiment, and the reflected acoustic signal of aluminum plate was detected at 10 m under water. According to the analysis of the experimental results, the maximum detection depth of an acousto-optic coupled interferometric hydrophone is 36m. Finally, a method of detecting the orientation and size of underwater targets by using laser source and acousto-optic coupled interferometric fiber-optic hydrophone array is presented, and its working principle is analyzed. The principle of using differential location algorithm and deconvolution algorithm to estimate the orientation and size of underwater target is introduced. Finally, the feasibility of this method is verified by numerical simulation of the detection system.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB565.1
【参考文献】
相关期刊论文 前1条
1 倪明,胡永明,孟洲,熊水东;数字化PGC解调光纤水听器的动态范围[J];激光与光电子学进展;2005年02期
，本文编号：2460847
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