Aspects of Signal Processing With Emphasis on Underwater Acoustics, Part 2

1. Front Matter

   Pages I-XI

   PDF

2. Subject 3

   1. Optimum Antenna Processing: A Modular Approach

      • C. Giraudon

      Pages 401-410

   2. The Forgotten Algorithm in Adaptive Beamforming

      • E. B. Lunde

      Pages 411-421

   3. The Effects of Signal and Weight Coefficient Quantisation in Adaptive Array Processors

      • J. E. Hudson

      Pages 423-428

   4. Adaptive Beamforming in an Active Doppler Sonar

      • J. N. Maksym

      Pages 429-441

   5. Adaptive Array Processing Experiments at HF

      • Lloyd J. Griffiths

      Pages 443-453

   6. Separation and Representation of Sources and Signals by a Linear Antenna

      • Hubert Debart

      Pages 455-461

   7. Complementarity of Propagation Model Design with Array Processing

      • H. Mermoz

      Pages 463-468

   8. Spectral Signal Set Extraction

      • Norman L. Owsley

      Pages 469-475

   9. A Constrained Adaptive Beamformer Tolerant of Array Gain and Phase Errors

      • J. M. McCool

      Pages 477-483

   10. Signal Extraction Algorithms for Adaptive Processing of Array Data

       • D. R. Farrier, T. S. Durrani

       Pages 485-494

   11. Properties of the Discrete Fourier Transform (DFT)

       • B. W. Conolly

       Pages 495-516

   12. An Adaptive Beamformer which Implements Constraints Using an Auxiliary Array Preprocessor

       • LLoyd J. Griffiths

       Pages 517-522

3. Displays, Pattern Recognition, Human Decision

   1. Front Matter

      Pages 523-523

      PDF

   2. Error and Reject Tradeoff for Nearest Neighbor Decision Rules

      • Pierre A. Devijver

      Pages 525-538

   3. Two-Dimensional Spectral Analysis for Image Coding, Processing and Recognition: An Approach Based on Some Properties of the Human Visual System

      • C. Braccini, G. Gambardella

      Pages 539-559

4. Relevant Inputs from Other Fields

   1. Front Matter

      Pages 561-561

      PDF

   2. Spectrum Analysis

      • C. v. Schooneveld, P. J. A. Prinsen

      Pages 563-590

   3. Autoregressive and Maximum Likelihood Spectral Analysis Methods

      • R. T. Lacoss

      Pages 591-615

   4. Confidence Intervals for Maximum Entropy Spectral Estimates

      • A. B. Baggeroer

      Pages 617-630

This paper describes the results of current research at DREA in which techniques of optimum array processing are being applied to active sonar. We are presenting these results at the Advanced Study Institute in order to illustrate some actual applications for such processing and to point out some of the practical considerations which arise in real systems. In particular, the paper concerns the problems which arise when the individual sensor elements have a complicated directivity pattern themselves. This is a common phenomenon in active systems where the receiving sensors are complex resonant structures and are housed in a dome or towed body presenting various baffling and diffraction effects. Most treatments of array processing consider ideal elements which have well behaved directivity properties and are transparent to the field. The results of this paper show that where these properties are not met, careful in situ array measurements are required, and even with such measurements practical array gains may not be as good as predictions based on ideal sensors.

• Phase
• acoustics
• coding
• communication
• discrete Fourier transform
• entropy
• pattern recognition
• signal processing
• signal processor
• ultrasound

• University of Genoa, Italy

  G. Tacconi

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