THE DETERMINATION OF FARFIELD CHARACTERISTICS OF LARGE, LOW-FREQUENCY TRANSDUCERS FROM NEARFIELD MEASUREMENTS

Abstract

The theory was developed for the computation of directivity patterns and source levels of a transducer from nearfield pressure amplitude and phase data. Preliminary work with 4 types of transducers in open water showed good agreement between measured and computed patterns. Extensive work was done with an AN/SQS-4 Mod 3 transducer and agreement between measured and computed patterns has been as good as !1 db in the more recent work. This includes measurements made in open water and in a highly reflective tank. Tank measurements were made near the leading edge of the received pulse; that is, before reflections from the tank walls could interfere. The tank diameter was only 2.9 times that of the transducer. In several cases source level was computed with the patterns and proved to be within !1 db of measured values in each case. Some work was done on a simplified nearfield test for large low-frequency transducers.

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Document Details

Document Type
Technical Report
Publication Date
Mar 15, 1962
Accession Number
AD0273522

Entities

People

  • D. D. Baker

Organizations

  • University of Texas at Austin

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Acoustics
  • Agreements
  • Calibration
  • Computations
  • Frequency
  • Geometry
  • Leading Edges
  • Measurement
  • Military Research
  • Navy
  • Open Water
  • Phase Measurement
  • Physics Laboratories
  • Pressure Gradients
  • Test And Evaluation
  • Transducers
  • Undersea Warfare

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Fluid Dynamics.
  • Phased Array Antenna Design.