Elastic Pekeris waveguide normal mode solution comparisons against laboratory data.

Area of Science:

• Geophysics
• Acoustics
• Wave Propagation

Background:

• The Pekeris waveguide problem is fundamental in underwater acoustics.
• Previous models often simplified the seabed as a fluid or rigid layer.
• Elastic properties of the seafloor significantly influence acoustic wave propagation.

Purpose of the Study:

• To outline a normal mode solution for the Pekeris waveguide problem considering an elastic bottom.
• To validate the analytic solution against experimental acoustic data.
• To assess the impact of horizontal wavenumber accuracy on model performance.

Main Methods:

• Derived a normal mode solution based on the Press and Ewing (1950) formulation.
• Utilized experimental data from a Naval Research Laboratory study (Collis et al., 2007).
• Benchmarked the analytic solution by comparing predicted and measured acoustic field characteristics.

Main Results:

• The derived normal mode analytic solution demonstrates a close agreement with experimental data.
• Horizontal wavenumber spectra from the model closely match those obtained from the experiment.
• Model accuracy is highly sensitive to the precise determination of horizontal wavenumbers.

Conclusions:

• The normal mode solution provides a reliable method for modeling acoustic propagation in Pekeris waveguides with elastic seabeds.
• Experimental validation confirms the efficacy of the derived analytic approach.
• Accurate characterization of horizontal wavenumbers is essential for predictive acoustic modeling in complex environments.