基于波导不变量的空中和水下声源分辨方法

An approach to distinguish air-borne and underwater sound source utilizing waveguide invariant

波导不变量反映了水下声场多途传播的干涉结构特征。将波导不变量的提取分析应用于空气中声源产生的水下声场,通过数值仿真分析了波导不变量分布随深度的变化,提出了利用小深度接收声场提取的波导不变量分布来分辨空中和水下声源的方法。分析了空气中声速和风速剖面对该方法的影响,指出在实际海上环境条件下,当出现逆温现象或者当接收器在声源下风方向时,该方法是有效的。

The waveguide invariant characterizes the dispersive nature of the waveguide and relates the observed slope of the striations to range and frequency. Waveguide invariant theory is applied to underwater sound field generated by an air-borne sound source. The relation of height or depth of source or receiver and the distribution of the waveguide invariant is studied by numerical simulation. A new approach utilizing the waveguide invariant in the water near the surface can distinguish air-borne and underwater sound source. The effects of sound speed profile and wind speed profile in the air on the approach are studies by numerical simulation. In actual atmospheric environment over ocean, this approach works when there is an inversion or when the receiver is downwind of the sound source.