仿鲸whistles叫声的抗混响主动声呐探测方法

Bionic covert anti-reverberation active sonar detection method based on imitating whale whistles

基于仿鲸叫声的伪装隐蔽探测方法,能够解决远距离探测和隐蔽性探测之间的权衡这一传统难题,近年来受到了极大关注,但在强混响条件下,基于匹配滤波的传统回波信号处理方法会受到极大干扰。本文提出了一种仿鲸whistles叫声的伪装声呐波形设计及计算高效的抗混响回波信号处理方法。一方面,提出了一种适用于强混响条件下的仿鲸声伪装声呐波形设计方法,该方法使用线性调频(linear frequency modulation,LFM)信号替换真实鲸叫声中的类LFM片段,并提取了真实鲸叫声类LFM片段的包络对该LFM信号进行修饰,通过比较伪装探测信号和真实鲸叫声时频轮廓的皮尔逊系数,证明了该方法在不影响隐蔽性的前提下完成了LFM信号的替换。另一方面,提出了一种基于同步信号定位目标回波的分数阶傅里叶变换回波信号处理方法,该方法使用同步信号定位目标回波,并基于同步信号携带的信息确定分数阶傅里叶变换的步长区间。相比于传统的分数阶傅里叶变换,该方法在有效减少计算量的同时,其抗混响能力也得到了提升。最后,通过仿真结果验证了所提方法的优异性。

The disguised covert detection method that imitates whale calls has received great attention in recent years because it can solve the traditional problem of the trade-off between long-range detection and covert detection.However,under strong reverberation conditions,traditional echo signal processing methods based on matched filtering will be greatly disturbed.Based on this,a disguised sonar signal waveform design is proposed based on imitating whale calls and computationally efficient anti-reverberation echo signal processing method.Firstly,this article proposed a disguised sonar signal waveform design method based on imitating whale calls.This method uses linear frequency modulation(LFM)signals to replace LFM-like segments in real whale calls,and extracts the envelope of the real whale call’s LFM-like segment to modify the LFM signal.Secondly,this article proposed an echo signal processing method of fractional Fourier transform(FrFT)based on target echo locating of synchronization signals.This method uses the synchronization signal to locate the target echo,and determines the step-size interval of the FrFT based on the information carried by the synchronization signal.Compared with the traditional FrFT,this method effectively reduces the amount of calculation and also improves the anti-reverberation ability.Finally,the excellent performance of the proposed method is verified by simulation results.