基于随机共振的水下目标微弱回波信号增强检测

Weak echo signal enhancement detection of underwater targetsbased on stochastic resonance

针对低信噪比下主动声呐探测水下目标的微弱回波信号检测难题,本文提出了一种基于随机共振的微弱回波信号增强检测方法。该方法通过建立频移变尺度随机共振系统,与输入高频微弱回波信号、随机噪声相匹配,实现微弱回波信号的共振增强;进而利用乘积谱与谱峭度构建目标回波亮点增强检测指标,有效提升微弱回波亮点的能量集中程度,抑制杂波及虚假成分干扰。仿真结果表明:在低信噪比下,随机共振系统输出信噪比增益可达5 dB以上,微弱目标回波亮点检测结果更加直观便捷,杂波干扰得到大幅抑制。海试数据处理结果进一步验证了所提方法的有效性和可靠性。

To solve the problem of detecting weak echo signal of underwater targets by active sonars at a very low signal to noise ratio(SNR),this study proposes a weak echo signal enhancement detection method based on stochastic resonance(SR).In this method,a frequency-shifted and re-scaling stochastic resonance system is established to match the weak high-frequency echo signal and random noise to output an enhanced weak echo signal.Furthermore,an enhancement detection index based on the product spectrum and spectral kurtosis is constructed to effectively improve the energy concentration of the weak echo highlight,and suppress the interference of clutter and false components.The simulation results show that at a low input SNR,the output SNR gain of the stochastic resonance system can reach more than 5 dB.The detection results of weak target echo highlights are more intuitive and convenient,and the clutter interference is greatly suppressed.The effectiveness and reliability of the proposed method are further verified by the processing results of sea experimental data.