Computer Programs to Calculate Normal Mode Propagation and Applications to Analysis of Explosive Sound Data in the BIFI Range

Abstract

This report describes two computer programs that use normal mode theory to predict acoustic propagation and discusses the use of these programs in analyzing explosive data taken in a series of shallow water tests. Program S1441 calculates normal mode propagation in a medium in which the stratification is constant with range; program S1548 computes normal mode propagation when the horizontal stratification is assumed to vary slowly with range. The range of the tests indicate that the introduction of horizontal stratification in program S1458 provides an improved comparison with measured data. Physical explanations are provided for the previously observed minimum in propagation loss at about 125 Hz and for the nonlinear relationship, at certain frequencies, between propagation loss and size of the negative sound gradient observed. In addition, bottom loss was determined in the BIFI (Block Island Fishers Island) range for a wide range of frequencies and thermal conditions.

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Document Details

Document Type
Technical Report
Publication Date
Nov 06, 1972
Accession Number
AD0905182

Entities

People

  • William G. Kanabis

Organizations

  • Naval Underwater Systems Center

Tags

Communities of Interest

  • Air Platforms
  • Counter IED
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustic Properties
  • Acoustic Waves
  • Acoustics
  • Angle Of Incidence
  • Block Island
  • Bottom Loss
  • Computer Programs
  • Computers
  • Frequency
  • Group Velocity
  • Phase Velocity
  • Physics Laboratories
  • Shallow Water
  • Standing Waves
  • Test And Evaluation
  • Wave Equations

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Oceanography.