简正波的干涉特性及耦合机理

Interference characteristics and coupling mechanism of normal mode wave

简正波理论对计算海洋声场十分重要,本文利用镜像法推导了简正波方程,得到的结果与求解赫姆霍兹方程得到的结果一致,利用镜像法可以准确直观地理解简正波的物理意义。简正波是海洋界面反射波在海洋中发生干涉现象形成的,其原理和光栅衍射类似。简正波耦合的机理是海洋介质的不均匀性造成简正波产生附加相位变化,破坏了不同简正波之间的正交性。

Normal mode methods have been used for many years in underwater acoustics. Normal mode equitation focusing on virtual image array theory agrees with the result by solving Helmholtz equation, virtual image array theory if of direct view and accuracy in explaining normal mode equitation. The principle of normal mode wave is similar to that of grating diffraction . Normal mode wave coupling comes from the loss of normal mode orthogonality for additional phase difference that is caused by oceanic nonunifonnity.