爆炸信号中气泡脉动去除方法及其应用

水下爆炸声源激发的声信号包括冲击波和气泡脉动,气泡脉动严重干扰冲击波的传播特性。当气泡脉动的幅度小于冲击波的幅度时,通过对此类混合爆炸信号进行复倒谱分析,提出了基于卷积型的爆炸信号模型的同态解卷积气泡脉动去除方法,其中,针对同态滤波系统中通常采用的“梳状”滤波器会在倒谱的尖峰处产生不连续点的问题,采用了对尖峰附近的采样点进行多项式函数拟合,并根据拟合函数对尖峰采样点插值的改进型滤波方法。数值仿真和实验信号的处理及分析表明,应用该方法可以明显消除爆炸信号自相关曲线中由气泡脉动造成的对称次尖峰,并在信号的时频分布图中再现冲击波的简正波特性。这为进一步利用爆炸声源研究海洋信道的声传递函数和反演海洋环境参数提供了技术途径。 

The method of bubble pulse removal from explosive signals and its application

An under-water explosive source signal is composed of a shock wave and several bubble pulses which can seriously interfere with the transmission of shock wave.The composite signal can be presented with a convolving model. When the amplitude of the bubble pulse is smaller than that of the shock wave,based on the complex cepstrum analysis of the explosive signal,a homomorphic deconvolving bubble pulse removal method is proposed.To avoid the discontinuity caused by the commonly used comb-like filter in homomorphic systems,an improved filter with a polynomial fitting is brought up.The results of numerical and experimental data processing show that,the bubble-pulse-caused symmetrical hypo-peaks in auto-correlations of explosive signals are effectively eliminated;the normal modes of an explosive shock wave are reconstructed in its time and frequency representation.This is important as a technical approach to both studies of sound transfer functions of ocean channels and geoacoustic inversion with explosive sources.