The KRAKEN Normal Mode Program

Abstract

In the late 1970's several normal-mode models existed which were widely used for predicting acoustic transmission-loss in the ocean; however, each had its own problems. Typical difficulties included numerical instabilities for certain types of sound-speed profiles and failures to compute a complete set of ocean modes. In short, there was a need for a model that was robust, accurate, and efficient. In order to resolve these problems a new algorithm was developed forming the basis for the KRAKEN normal mode model. Over subsequent years, KRAKEN was greatly extended, with options for modeling ocean environments that are range-independent, range-dependent or fully 3-dimensional. The current version offers a specialist a vast number of options for treating ocean-acoustics problems (or more generally acousto-elastic waveguides). On the other hand, it is easy for a less sophisticated user to learn the small subset of tools needed for the common problem of transmission-loss modeling in range-independent ocean environments. This report addresses the need for a more complete user's guide to supplement the on-line help files. The first chapters give a fairly technical description of the mathematical and numerical basis of the model. Additional chapters give a simpler description of its use and installation in a manner that is accessible to less scientifically-oriented readers.

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Document Details

Document Type
Technical Report
Publication Date
May 22, 1992
Accession Number
ADA252409

Entities

People

  • M. B. Porter

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustic Waves
  • Acoustics
  • Attenuation
  • Computer Programs
  • Convergence Zones (Sonar)
  • Difference Equations
  • Differential Equations
  • Eigenvalues
  • Elastic Properties
  • Gulf Stream
  • Losses
  • Oceans
  • Refraction
  • Three Dimensional
  • Transmission Loss
  • Two Dimensional
  • Waveguides

Readers

  • Computational Fluid Dynamics (CFD)
  • Systems Analysis and Design
  • Wave Propagation and Nonlinear Chaotic Dynamics.