分层砂底对浅海信道声传播影响的研究  

Research on effects of the sand seafloor on acoustic waves in an underwater acoustic channel

作　　者：马黎黎[1] 王仁乾[1] 

机构地区：[1]北京大学电子学系,北京100871

出　　处：《声学学报》2003年第2期145-150,共6页Acta Acustica

摘　　要：推导有指向性脉冲声源在海底是分层结构的浅海中声场的积分表达式;分别仿真了爆炸声源和指向性脉冲源在浅海信道中传播的信号波形,其中假设了海底的沉积层和基底分别由水浸泡的砂和固态介质构成,砂底的参数数值用孔隙介质理论和实测相结合的方法进行选择;此外,在用砂和玻璃珠分别模拟砂层海底的水池内,观测了指向性脉冲源在不同接收点的信号的波形;结果表明:仿真波形的包络得到实验的印证。从而证明本文建立的指向性脉冲源在具有砂层海底的浅海中声场模型是可行的,可用于预报海洋环境参数对接收波形的影响,为水下通信、声呐信号设计与处理提供参考信息。An integral expression for sound field of directional and pulsed source in shallow water with layered seafloor is derived. It is supposed that sediment and basc of seafloor are composed of water-saturated sand and solid media respectively. The values of acoustic parameters of the water-saturated sand are selected from calculating results according to the theory of porous medium model and experimental results. The synthetic full waveforms of sound pressure in the shallow water are simulated from the integral expression for sound field for the explosive point black source and directional and pulsed source. Experiments were carried out in the pool which the sediment of pool bed is composed of water-saturated sand or crystal balls: a directional transducer emits sine signal modulated by a square wave, the received waveforms were recorded at different received points.The features of the recorded waveform envelopes are much similar to the simulated results. This result proves the model, set up by this paper, of sound propagation in the shallow water with the layered sand floor is advisable. It can predict that parameters of ocean environment effect on the waveforms received in the shallow water, so that as a reference information provided to design and process signal for underwater communication and sonar system.The attenuation and dispersion of a normal - mode are simulated for sand, uniformity liquid-state and solid-state bottom. The simulative results are compared each other so that find out the feature of the effects of the sand floor on sound wave propagation.

关 键 词：分层砂底 浅海信道 声传播 仿真 海洋声学 水下通信 声场 

分 类 号：P733.2[天文地球—物理海洋学]