Modeling scattering from azimuthally symmetric bathymetric features using wavefield superposition.

Area of Science:

• Acoustics
• Oceanography
• Geophysics

Background:

• Modeling seafloor bathymetry is crucial for understanding acoustic wave propagation.
• Azimuthally symmetric features like seamounts and basins are common on the seafloor.
• Accurate scattering models are needed for high-frequency and low-frequency acoustic applications.

Purpose of the Study:

• To develop and present an approach for modeling acoustic scattering from azimuthally symmetric bathymetric features.
• To adapt existing numerical methods for partially buried targets to this specific problem.
• To provide a benchmark solution for a class of penetrable seafloor features.

Main Methods:

• Utilized wavefield superposition to model scattering.
• Exploited azimuthal symmetry to reduce 3D scattering to a sum of 2D problems.
• Derived a semianalytic coupled mode solution for density-contrast half-spaces.

Main Results:

• Demonstrated the applicability of wavefield superposition for modeling scattering from bathymetric features.
• Provided a benchmark solution for penetrable hemispherical indentations or bosses.
• Presented example computations across a wide frequency band for a simple seabed scattering feature.

Conclusions:

• The wavefield superposition method is effective for modeling acoustic scattering from azimuthally symmetric seafloor features.
• The derived semianalytic solution serves as a valuable benchmark for validating numerical methods.
• The approach is applicable to a range of seafloor topographies and acoustic frequencies.