Shallow Water RASP Upgrade

Abstract

The Range Dependent Active System Performance model (RASP) has been modified to function at higher frequencies in shallower water than its initial design specification. The major difficulties in the original version of the model were the control of the cubic spline fitting routines to the sound speed points, extension of attenuation coefficients to higher frequencies and the need to interface to Navy standard data bases (or models) for bottom loss calculations. These two areas of difficulty were overcome using a front end sound speed fitting algorithm based on cubic splines under tension to control the oscillations in the spline fits in the model, and subroutines to allow input of standard bottom loss curves. The resulting modifications to the model created a model capable of predicting range dependent monostatic reverberation (with reasonable accuracy) at frequencies up to kHz. The modifications did not address the broader problem of bistatic range dependent reverberation at high frequencies (or in shallow water), or the problem of energy splitting loss on predicted target returns.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1991
Accession Number
ADA237976

Entities

People

  • J. K. Fulford

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustics
  • Backscattering
  • Bottom Loss
  • Boundaries
  • Computer Programs
  • Databases
  • Echoes
  • Frequency Bands
  • Grazing Angles
  • Military Research
  • Ray Tracing
  • Reverberation
  • Scattering
  • Signal Processing
  • Standards
  • Target Echoes
  • Transmission Loss

Readers

  • Computational Modeling and Simulation
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Wave Propagation and Nonlinear Chaotic Dynamics.