A Constructive Algorithm for Determining Array Shape with Application to FREDDEX.

Abstract

Long, towed hydrophone arrays are useful in a sonar context as high-gain, high-resolution receivers. However, conventional beamforming assumes a straight, horizontal aperture. Towed arrays undergo dynamic shape changes due to ship track instabilities and to subsurface currents. This report documents a constructive algorithm for determining array shape as well as the results of using this algorithm to determine array shapes from the Spring 1979 FREDDEX experiment. It is shown that the algorithm works successfully on this data set and indicates that array deformation for FREDDEX was minimal. A typical value for the standard deviation of the array was 0.2 m. The lowest spatial mode (the bow shape) predominated and cycled in about 16 min. Acoustic degradation was evaluated for several frequencies and was always well below one dB. Increased sidelobes were apparent, but they were still 35 dB below the maximum response. (Author)

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1981
Accession Number
ADA107923

Entities

People

  • Donald R. Del Balzo
  • Lawrence J. Rosenblum

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Advanced Electronics
  • Ground and Sea Platforms
  • Sensors
  • Space

DTIC Thesaurus Topics

  • Accuracy
  • Acoustic Detectors
  • Acoustic Measurement
  • Acoustics
  • Computations
  • Crossings
  • Data Processing
  • Data Sets
  • Detection
  • Errors
  • High Gain
  • High Resolution
  • Histograms
  • Interpolation
  • Linear Arrays
  • Standards
  • Towed Arrays

Readers

  • Marine Hydrodynamics
  • Oceanography.
  • Radar Systems Engineering.