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A Stable Phantom Material for Optical and Acoustic Imaging
Published on: June 16, 2023
Ray-based description of normal modes in a deep ocean acoustic waveguide
A L Virovlyansky1, A Yu Kazarova, L Ya Lyubavin
1Institute of Applied Physics, Russian Academy of Science, Nizhny Novgorod, Russia.
The Journal of the Acoustical Society of America
|March 12, 2009
Summary
This study analyzes acoustic wave propagation in deep ocean sound channels affected by internal waves. It provides analytical estimates for how sound energy distributes among modes and how individual mode pulses change over long distances.
Area of Science:
- Ocean acoustics
- Wave propagation physics
- Underwater sound
Background:
- Ocean environments exhibit complex sound speed profiles due to internal waves.
- Understanding acoustic modal structure is crucial for long-range underwater sound propagation.
- Previous models often simplify the effects of random sound speed fluctuations.
Purpose of the Study:
- To develop an approximate analytical description of acoustic modal structure in deep ocean environments with random internal waves.
- To estimate the distribution of acoustic energy among normal modes for monochromatic fields.
- To analyze the characteristics of mode pulses, including their travel time and spread.
Main Methods:
- Combining ray path parameters with stochastic ray theory for modal structure analysis.
- Deriving analytical estimates for coarse-grained energy distribution between normal modes.
- Calculating analytical estimates for mode pulse spread and mean travel time bias.
Main Results:
- An approximate analytical description of modal structure at megameter ranges was derived.
- A simple analytical estimate for the coarse-grained distribution of acoustic energy among normal modes was obtained.
- Analytical estimates for mode pulse spread and bias in mean travel time were derived.
Conclusions:
- The study provides a framework for understanding acoustic propagation in complex ocean sound channels.
- The derived estimates are valuable for predicting signal characteristics over long distances in the presence of internal waves.
- This research contributes to the field of underwater acoustics and signal processing.
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