Unambiguous Triplet Array Beamforming and Calibration Algorithms to Facilitate an Environmentally Adaptive Active Sonar Concept

Abstract

Cardioid or triplet towed arrays are utilized in sonar applications to resolve left/right ambiguity by placing a null on the ambiguous direction. This leaves an uncalibrated residual signal on the opposite direction from which the desired signal is arriving. Here the mechanism of cardioid beamforming is presented and analytical expressions for the calibration of continuous wave (CW) and linear frequency-modulated (LFM) signals are derived. The validity of these expressions is verified using simulated and real data. The same data sets are also used for comparing the performance between the standard beamformer and a modified version designed to suppress endfire singularities. The effect of correlated vs. uncorrelated intratriplet noise is assessed using a simulation scenario with a point target.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2006
Accession Number
ADA492297

Entities

People

  • Alberto Baldacci
  • George Haralabus

Organizations

  • Centre for Maritime Research and Experimentation

Tags

Communities of Interest

  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Active Sonar
  • Algorithms
  • Arrays
  • Bandwidth
  • Beam Forming
  • Calibration
  • Coefficients
  • Detection
  • Detectors
  • Equations
  • Filters
  • Frequency
  • Hydrophones
  • Matched Filters
  • Noise
  • Sonar
  • Steering

Fields of Study

  • Engineering

Readers

  • Phased Array Antenna Design.
  • Radar Systems Engineering.