An Evaluation of Methods for Characterizing the Air/Water Interface for Parabolic Equation Transmission Loss Modeling

Abstract

Proper characterization of underwater acoustic transmission loss (TL) relies on proper treatment of the air/water and water/sediment interfaces. This paper will focus on how the air/water interface is treated in parabolic equation (PE) models such as the range dependent acoustic model (RAM) [Collins, M. D., "Applications and time-domain solution of higher-order parabolic equations in underwater acoustics," J. Acoust. Soc. Am., 86 (3), 1097-1102, 1989] and the finite element parabolic equation (FEPE) model [Collins, M.D., "A higher-order parabolic equation for wave propagation in an ocean overlying an elastic bottom", J. Acoust. Soc. Am. 86, 1459-1464, 1989]. Two surface loss methods have been implemented in RAM, a surface loss versus angle (LVA) and a conformal mapping (CM) method. Additionally, the CM method has been implemented in FEPE. These two methods are discussed and compared for realistic test cases and a third option, which has accuracy consistent with the CM but speed more aligned with the LVA approach is discussed.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2010
Accession Number
ADA527611

Entities

People

  • Guy Norton
  • J. P. Fabre
  • Richard Keiffer
  • Robert Zingarelli

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Accuracy
  • Acoustic Fields
  • Acoustic Phenomena
  • Acoustic Propagation
  • Acoustics
  • Conformal Mapping
  • Equations
  • Frequency
  • Geometry
  • High Angles
  • Losses
  • Refraction
  • Reliability
  • Scattering
  • Surface Roughness
  • Transmission Loss
  • Wave Propagation

Readers

  • Acoustical Oceanography.
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)