水中分层弹性球壳高频时域回波的声学编码研究

Acoustic coding based on high frequency time domain echo of layered elastic spherical shells in water

针对水下集群目标及敌我目标识别的难题,该文提出了一种基于水中分层弹性球壳高频时域回波的声学编码原理及方法。推导了水中4层弹性球壳目标散射声压的简正级数解,并与有限元结果进行了对比验证。通过构造高频主动声呐的探测脉冲信号,与4层弹性球壳声传递函数的简正级数解做卷积运算,获得了目标的时域回波脉冲序列。研究了分层弹性球壳的厚度、各层材料属性、排布顺序等对时域回波特征的影响规律,提出了基于时域回波特征的声学编码方法。研究表明:利用水中分层弹性球壳目标高频时域回波特征能够实现声学编码,回波结构稳定,且不受限于探测方向。通过携带或安装这种分层弹性球壳结构,有望识别水下航行体/悬浮体等目标。该文的研究对水下目标的主动探测身份识别及导航等具有一定的参考价值。

For the difficult problem of underwater cluster target and enemy target identification,an acoustic coding principle and method based on the high-frequency time-domain echo of layered elastic spherical shells in water is proposed in this paper.The simple positive series solution of the scattered acoustic pressure of a target with four layers of elastic spherical shells in water is derived and compared with the finite element results for verification.The time-domain echo pulse sequence of the target is obtained by constructing the detection pulse signal of high-frequency active sonar and doing the convolution operation with the simple positive series solution of the acoustic transfer function of the four-layer elastic spherical shell.The influence law of the material thickness properties and arrangement order of each layer of the layered elastic spherical shell on the time-domain echo characteristics is studied,and the acoustic coding method based on the time-domain echo characteristics is proposed.It is shown that the acoustic coding can be achieved by using the high-frequency time-domain echo characteristics of the layered elastic spherical shell target in water,and the echo structure is stable and not limited by the detection direction.By carrying or installing this layered elastic spherical shell structure,targets such as underwater navigable/suspended bodies are expected to be identified.The research in this paper has some reference value for active detection identification and navigation of underwater targets.