Coupled Normal Mode Numerical Modeling In Shallow-water Range-dependent Waveguide

Acoustic propagation is essence content in ocean acoustics. As a forward problem, it is the basic of backward problem such as acoustic detection and tomography. In real ocean channel, surface and water column is space-time variability that can' t be ignorable, and makes the sound wave propagated in it abnormal and fluctuant. In order to mastery rule of acoustic propagation, and model the wave field quickly, this paper studies the modeling of range-dependent waveguide with space variability using coupled normal mode. Based on wave propagation theory, the paper describes briefly basic principle of several acoustic propagation models, and discusses detailedly foundation of coupled normal mode. WKBZ theory is used to solve the eigen-value and eigen-vector of normal mode equation, for the sake of settling out the disadvantage of long computing time in COUPLE 97 mode. The operating time of new coupled normal mode model (CNM) is reduced effectively, meantime precision is improved slightly. Finally, in the paper, CNM is compared with other model, is validated with JASA Benchmark and ASIAEX experiment data under several acoustic propagation environments. Results indicate that CNM can modeling acoustic propagation accurately with good precision and fast operating timeo...