浅海声信道中的声纳脉冲传播多途效应

多途效应是水声信号传播的重要现象，对声纳信号的检测与参数估计有较大影响；利用简正波理论，对声纳脉冲在浅海传播过程中的多途效应进行理论分析，结合信号处理理论，给出了接收信号波形计算方法，仿真计算了浅海等温层、负梯度以及负跃层3种典型传播条件下的信道频率响应函数和声纳脉冲信号波形，分析了声速剖面类型、收发深度、接收距离以及海底底质等因素对脉冲声传播多途效应的影响。

Multipath Effect of Sonar Pulse Waveforms in Shallow Water

Multipath effect is an important phenomenon of underwater signal propagation, which badly in-fluenced the detection of sonar signal and estimation of the parameter. In this paper, the normal modes theory is used to analyze the multipath effect in theory when sonar pulse waveforms were propagated in shallow water. Based on signal processing theory, the method of back wave form calculation is given, and the underwater acoustic channel＇ s frequency response function and sonar pulsed waveforms in three typical conditions which conclude isothermal layer in shallow water, negative gradient and negative thermocline are simulated. What＇s more, we analyzed the multipath effect influenced by primary factors such as, type of acoustic speed profile, depth of emitter and receiver, distance and seabed type.