MATLAB激光侦听中音频信号仿真提取方法研究
关键词 激光侦听器 反射 干涉 声光效应 声压振动
毕业论文设计说明书外文摘要
Title: Extraction Method Laser Listeners In An Audio Signal Simulation
Abstract
The paper concludes and studies the theory of laser optics monitor as well as the working principle of laser monitor. According to the experimental conditions, the paper analyzed solution for the laser monitoring technology and provided exploration and discussion for the characteristics, signal loading principles and extractions of reflective, interferometric and acoustic and light modulator laser monitor experimental scheme, and discussed the signal enhancement principles of monitoring light path under the "cat's eye". The receiver adopted a photoelectric receiver to collect laser monitoring signals, design a feedback to amplify the audio signal in the monitoring signals extracted from circuits, using the MATLAB toolbox to stimulate the echo signal in the interferometric monitoring system, stimulating the monitoring audio signal with noise and conduct comparative study on the characteristics of the monitoring signals. On this basis, the paper discussed the reduction and the amplification technology of the audio signal and gave analysis on the drawbacks of the experiment and environmental impact on the experiment.
Keywords Laser listener Reflection Interference
Acoustic optic effect Acoustic pressure vibration
目 次
1 引言 1
1．1 概述 1
1．2 本文工作 2
2 激光侦听器的理论基础及设计方案 4
2．1 激光光源 4
2．2 反射式激光侦听器理论基础 5
2. 3 “猫眼”侦听方法优化设计 7
3 激光侦听实验 9
3. 1 干涉式实验 9
3. 2 反射式实验 10
3．3 声光效应 11
4 数据分析与仿真 12
4. 1 干涉式激光侦听波形图及频域图 12
4. 2 声光实验数据 12
4．3 Simulink仿真 16
4．4 激光侦听实验结果 20
5 激光侦听器声音信号还原与放大 22
5. 1 PSD传感器的激光语音还原 22
5. 2 反馈网络放大信号 24
5. 3 环境、角度对实验的影响 25
结 论 26
致 谢 27
参考文献28
1 引言
1.1 概述
1.1.1 研究背景
激光侦听技术已发展多年，光源技术的日益发展，机理在实验研究中也逐渐走入成熟，并逐步实际运用，市场中也开始出售类似于激光侦听器的设备。国内外的一系列研究使得技术发展成熟，但由于国内的类似产品侦听距离有限，所以国内市场中并未出现，仅用于刑侦和军事。然而非现场信息的获取在当今社会应用非常广泛，尤其是对于民事案件侦破、获取重要军事情报使用这种方法。虽然入们熟知电子设备的侦听技术，但是其存在一些弊端。最大的缺陷是在被监听者处设置电子设备很容易被反侦察导致听失败。激光技术中的侦听器则是利用光的反射原理，无需在侦听对象处事先摆放麦克风一类的电子装置，电子侦听器的缺陷可以被很好改善【1】。