基于Hilbert变换的水下多源声信号频率的相干探测

发布时间：2018-02-16 19:24

本文关键词： 水下声信号频谱分析激光干涉信号解调 Hilbert变换声光效应声波传播　出处：《光子学报》2017年07期 　论文类型：期刊论文

【摘要】：为实现水下中低频声信号的探测识别,通过研究水下多声源相干探测信号的特征,理论上给出了相干探测信号频谱混叠情况下的特征表达式,并提出了一种基于Hilbert变换的信号解调处理方法,实现了水下多声源相干探测信号频谱混叠情况下各声源发声频率的解调.该方法将探测信号经过滤波平滑处理之后进行Hilbert变换,得到信号的解析形式,然后对解析信号模值的平方进行二次滤波平滑等处理,分离混叠在一起的频带,将得到的信号进行频谱分析,根据频移值计算得到水下各个声源的发声频率.在光学暗室下搭建激光相干探测系统,对2~6kHz的水下声信号进行实验,实验结果表明,该方法可以有效分离探测信号中混叠在一起的信号频带,并准确提取各水下声信号的发声频率,频率提取重复性不大于2.5Hz.
[Abstract]:In order to realize the detection and recognition of underwater low frequency acoustic signals, the characteristic expressions of coherent detection signals with multiple underwater sound sources are given in theory, in which the spectrum of coherent detection signals is overlapped. A signal demodulation processing method based on Hilbert transform is proposed to demodulate the sound frequency of each sound source in the case of spectrum aliasing of underwater multi-source coherent detection signal. The method performs Hilbert transform after filtering and smoothing the detection signal. The analytic form of the signal is obtained, then the square of the analytic signal modulus is processed by quadratic filtering and smoothing, and the aliasing frequency band is separated, and the frequency spectrum of the obtained signal is analyzed. According to the frequency shift, the sound frequency of each underwater sound source is calculated. The laser coherent detection system is built under the optical dark chamber, and the underwater acoustic signal of 2 ~ 6 kHz is tested. The experimental results show that, This method can effectively separate the aliasing signal frequency band in the detection signal and accurately extract the sound frequency of each underwater acoustic signal. The repetition of the frequency extraction is not more than 2.5 Hz.
【作者单位】：哈尔滨工业大学电气工程及自动化学院;中国电子科技集团公司第十研究所;上海卫星工程研究所;
【基金】：国家自然科学基金青年基金(No.61108073) 上海航天科技创新基金(No.SAST2015029) 博士后研究人员落户黑龙江科研启动资助金(No.AUGA4120006016)资助~~
【分类号】：TB566

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