平面冰层覆盖下水中声传播损失特性分析

CHARACTERISTIC ANALYSIS OF ACOUSTIC TRANSMISSION LOSS IN WATER UNDER PLANE ICE COVER

理论计算了冰层的声波反射系数,分析了平面冰层覆盖下水中声传播损失特性。将冰层视作平面覆盖层,建立了"空气-冰层-水"结构的冰层反射物理模型,结合冰中的物理声学参数,得到冰层反射系数;利用Bellhop海洋声学传播模型得到冰层覆盖下声场的传播损失,对比分析了传播损失与声波频率、声源深度的关系;结合冰层反射系数计算结果,解释了冰下信道具有频率选择性的原因。结果表明,冰层覆盖下声场传播具有明显的频率选择性,这种频率选择性是由声波频率和冰层厚度共同决定的。

The acoustic reflection coefficient of the ice layer is calculated, and the characteristics of acoustic propagation loss in the surface layer are analyzed. The ice layer is approximated as a flat cover, and a phys- ical model of ice reflection is established. The reflection coefficient of ice layer is calculated based on the physical acoustic parameters of ice. The sound field propagation loss under the ice cover is obtained using the Bellhop ocean acoustic propagation model, and the relationship between the propagation loss and the acoustic frequency or the sound source depth is analyzed. The reason for the frequency selectivity of the ice channel can be explained based on the calculation results of the reflection coefficient of the ice layer. The results show that the propagation of sound field under the ice cover has obvious frequency selectivity, which is determined by sound wave frequency and the thickness of the ice layer.