基于小波变换的水下声信号激光探测应用

Application of laser detection of underwater acoustic signals based on wavelet transform

为了进行激光探测水下声信号的研究,分析了水下声信号的激光干涉探测信号的时频分布特点,找到了激光干涉信号小波脊的分布规律。根据小波脊的分布规律,采用一种利用小波变换的水下声信号瞬时频率估算方法实现水下声信号瞬时频率的估计,并对稳频的水下声信号和线性调频的水下声信号进行了探测实验。结果表明,对频率变化率为16k Hz/s的水下声信号探测实验中,根据小波脊计算出水下声信号的瞬时频率,拟合得到水下声信号频率变化率为16.05k Hz/s。此结果验证了本文中所述方法的正确性。

In order to study underwater acoustic signals by laser detection and analyze the characteristic of time frequency distribution of underwater laser interference detection signals, the regularity of wavelet ridges distribution of laser interference signal was discovered. According to this regularity, a method for estimating the instantaneous frequency of underwater acoustic signal was put forward based on wavelet ridges. Detection experiments of underwater acoustic signal with stable-frequency and linearly-modulated frequency were both carried out. The results show that, in the detection experiment of underwater acoustic signal with frequency change rate of 16kHz/s, the fitness result of frequency change rate is 16.05kHz/s after wavelet ridges computation. The results prove this method is validated.