A higher-order split-step Fourier parabolic-equation sound propagation solution scheme

Area of Science:

• Oceanography
• Acoustics
• Computational Physics

Background:

• Accurate simulation of underwater sound propagation is crucial for naval applications and marine research.
• Existing numerical models often face limitations in handling complex ocean environments and acoustic phenomena.

Purpose of the Study:

• To present a novel three-dimensional Cartesian parabolic-equation model for simulating underwater sound propagation.
• To enhance the accuracy of acoustic simulations in ocean waveguides using a higher-order approximation.

Main Methods:

• Developed a 3D Cartesian parabolic-equation model incorporating a higher-order approximation for the square-root Helmholtz operator.
• Implemented a split-step Fourier algorithm to efficiently solve for sound pressure.
• Validated the model using two idealized ocean waveguide scenarios.

Main Results:

• The higher-order approximation effectively accounts for cross terms involving the free-space Helmholtz operator and medium phase speed anomalies.
• The split-step Fourier algorithm provides an efficient means to compute sound pressure.
• Demonstrated the model's capability to simulate sound propagation in idealized ocean waveguides.

Conclusions:

• The presented 3D model offers a more accurate approach to simulating underwater sound propagation.
• This higher-order parabolic-equation method is a valuable tool for understanding acoustic behavior in ocean waveguides.