Scattering from Marine Sediments in a Very Shallow Water Environment
Abstract
This paper describes a full-field perturbation approach to scattering and reverberation in complicated environments, such as range-dependent stratified media and waveguides with rough interfaces. Each interface is treated as a superposition of deterministic large-scale features (such as bathymetry changes) and random small-scale (comparable with the wavelength) roughness. Expressions for both reverberation field and average reverberation intensity in a general case of an arbitrary number of rough interfaces are obtained in a form, convenient for numerical simulations. In the case of long-range ocean reverberation, several approximations for these expressions are developed, relevant for various environmental scenarios and different types of interfaces, sea-surface, water-sediment interface, buried sediment interfaces, and bottom basement. The results are presented in a simple form and provide a direct relationship of reverberation intensity with three critical characteristics defined at each interface: (1) local spectra of small-scale roughness, (2) local contrast of acoustic parameters, and (3) two-way full-field transmission intensity calculated taking into account only large-scale changes of the environment.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 28, 2015
- Accession Number
- AD1001868
Entities
People
- Anatoliy N. Ivakin
Organizations
- Johns Hopkins University Applied Physics Laboratory