Fundamentals of Acoustical Oceanography (eBook)

Cover 1
Table of Contents 6
Series Preface 18
Author Preface 19
Acknowledgments 21
Chapter 1. The Realm of Acoustical Oceanography: Theory and Applications of Ocean Acoustics 22
1.1 Introduction 22
1.2 Physical and Biological Characteristics of the Sea 23
1.3 Ocean Stratification, Sound Speed, and Ray Refraction 25
1.4 A Few Examples of Acoustical Oceanography 27
Chapter 2. Sound Propagation 38
2.1 Wave Propagation 38
2.2 Huygens’ Principle for Impulse Waves 40
2.3 CW Sinusoidal Signals: Spherical Waves 45
2.4 CW Interference and Phase Effects 48
2.5 The Wave Equation 56
2.6 Reflection and Transmission at Interfaces 62
2.7 Propagation in Three Dimensions 79
Chapter 3. Transmissions along Ray Paths 91
3.1 Impulse and CW Propagation in Ocean Acoustics 93
3.2 Ray Paths, Ray Tubes, and Path Times 98
3.3 Ray Paths in a Lossless, Refracting Medium 105
3.4 Attenuation 124
3.5 Tomography 137
3.6 Doppler Frequency Shift 140
Chapter 4. Sources and Receivers 148
4.1 Transducer Elements 148
4.2 Arrays of Discrete Sources 154
4.3 Directivity of a Line Source 156
4.4 Circular Piston Source 159
4.5 Radiation from a Transducer 164
4.6 Equivalence of Source/Receiver Directivity 167
4.7 Free-Field Calibration of Transducers 170
4.8 Self-Reciprocity Calibration of Transducers 171
Chapter 5. High Intensities 174
5.1 Harmonic Distortion and Shock-Wave Growth 174
5.2 Cavitation 179
5.3 Parametric Sources and Receivers 183
5.4 Explosive Sources 191
5.5 Acoustic Radiation Pressure 198
5.6 Acoustic Streaming 199
Chapter 6. Processing of Ocean Sounds 204
6.1 Sampling Rules 205
6.2 Filter Operations 209
6.3 Gated Signals 220
6.4 Power Spectra of Random Signals 221
6.5 Matched Filters and Autocorrelation 230
6.6 Sounds in the Ocean 232
Chapter 7. Sound Scattered by a Body 255
7.1 Scattering Measurements: Incident Plane-Wave Approximation 256
7.2 Helmholtz-Kirchhoff Methods 262
7.3 Specular Backscatter by the Kirchhoff Method 270
7.4 Modal Solutions for a Fluid Cylinder 279
7.5 Scattering from a Sphere 288
Chapter 8. Bubbles 308
8.1 Scattering from a Spherical Gas Bubble: Modal Solution 310
8.2 Single Pulsating Bubbles: ka < <
8.3 Bubbly Water 331
8.4 Active Measurements in Bubbly Water 343
8.5 Sea Surface Microbubble Production 355
8.6 Bubbles in Sediments 362
Chapter 9. Biomass Echoes, Reverberation, and Scattering Models 369
9.1 Introduction to Bioacoustics 369
9.2 Sound Backscattered by a Fish: Echoes 371
9.3 Sound Backscattered by Many Bodies: Reverberation 374
9.4 Variability of Fish Structure and Sound Backscatter 384
9.5 Acoustical Models of Fish 393
9.6 Sound Backscattered by Zooplankton 412
9.7 Bubble-Carrying Plankton 422
9.8 Allometric Expressions for Zooplankton 422
Chapter 10. Sonar Systems: Measurements and Inversions 426
10.1 Types of Sonars 427
10.2 Sonar Systems: Details 437
10.3 In Situ Scattering-Length Measurements 451
10.4 Single Transducer Scattering Length Measurements 458
10.5 Interactions of Sonars and Fish Behavior: Simulations 470
10.6 Quantitative Reverberation Analysis: Zooplankton 479
Chapter 11. Waveguides: Plane Layers and Wedges 489
11.1 Normal Modes in Plane-Layered Media 490
11.2 Geometrical Dispersion: Phase and Group Velocities 507
11.3 Arrays, Signals, and Noise 514
11.4 Transmission Functions in Matrix Notation 520
11.5 Source Location 522
11.6 Range-Dependent Waveguide: Wedge 530
11.7 Parabolic Equation (PE) Method 535
11.8 Wedge Waveguide in the Time Domain: Biot-Tolstoy Method 537
Chapter 12. Scattering at Elements of a Rough Surface 562
12.1 The Helmholtz-Kirchhoff Integral for Surface Scatter 563
12.2 Implementation of Biot-Tolstoy Theory of Impulse Scatter from Wedges and Plates 563
12.3 Digital Calculations of Biot-Tolstoy Diffraction in the Frequency Domain 576
12.4 BT Wedge Assemblage Techniques: Rough Surfaces 590
Chapter 13. Scattering and Transmission at Statistically Rough Surfaces 598
13.1 Descriptions of Ocean Surfaces 599
13.2 Forward Scatter in the Specular (Mirror) Direction: Simple Concepts 614
13.3 Surface Scatter of Sound 627
13.4 Near Grazing Scatter at a Steep-Sloped, Rough Surface 648
13.5 Point-Source Transmission through a Rough Interface 653
Chapter 14. Mapping the Sea Floor 661
14.1 Bathymetric and Seismic Profiles: Geophysics 661
14.2 Deep-Tow Side-Scan Sonar Mapping of the Sea Floor 662
14.3 Swath Mapping from Surface Vessels 665
14.4 Analytical and Numerical Evaluations of the Scattering Coefficients 674
14.5 An Analysis of the Backscattered Data in Two Areas: Spatial Correlations 675
14.6 An Analysis of the Backscattered Data in Two Areas: Spatial Spectra 680
References 683
Bibliography 709
Symbols 713
Subject Index 729
Color Plate Section 734