Jackson / Richardson High-Frequency Seafloor Acoustics

1. Auflage 2007
ISBN: 978-0-387-36945-7
Verlag: Springer US
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 616 Seiten

Reihe: The Underwater Acoustics Series

This book is a research monograph on high-Frequency Seafloor Acoustics. It is the first book in a new series sponsored by the Office of Naval Research on the latest research in underwater acoustics. It provides a critical evaluation of the data and models pertaining to high-frequency acoustic interaction with the seafloor, which will be of interest to researchers in underwater acoustics and to developers of sonars. Models and data are presented so as to be readily usable, backed up by extensive explanation. Much of the data is new, and the discussion in on two levels: concise descriptions in the main text backed up by extensive technical appendices.

Autoren/Hrsg.

Jackson, Darrell

Richardson, Michael

Inhaltsverzeichnis

1;Acknowledgments;8
2;Contents;9
3;1 Introduction;15
3.1;1.1 Applications;16
3.2;1.2 Research on Seafloor Scattering;17
3.3;1.3 Organization of Monograph;18
4;2 Basic Concepts and Definitions;21
4.1;2.1 Geophysical Properties;21
4.2;2.2 Sediment Wave Theories;28
4.3;2.3 Reflection and Scattering;31
5;3 The Nature of Marine Sediments;42
5.1;3.1 The Origin and Classification of Coastal Sediments;43
5.2;3.2 Sediment Structure;45
5.3;3.3 Bubbles in Sediment;64
5.4;3.4 Effects of Hydrodynamic and Biological Processes;70
5.5;3.5 Research Issues;85
6;4 Physical Properties;87
6.1;4.1 Sediment Grain Size Distribution;88
6.2;4.2 Sand Grain Morphology;101
6.3;4.3 Phase Relationships: Porosity, Void Ratio, Water Content, and Bulk Density;104
6.4;4.4 Sediment Conductance;111
6.5;4.5 Grain Properties;122
6.6;4.6 Factors Affecting Fluid Motion;130
6.7;4.7 Pore Water Properties;131
6.8;4.8 Research Issues;134
7;5 Geoacoustic Properties;135
7.1;5.1 Compressional Wave Speed and Attenuation;137
7.2;5.2 Shear Wave Speed and Attenuation;163
7.3;5.3 Biot’s Slow Wave ;173
7.4;5.4 Sound Speed and Attenuation versus Frequency;177
7.5;5.5 Bulk Density Regressions;179
7.6;5.6 Properties of Rock;181
7.7;5.7 Research Issues;182
8;6 Seafloor Roughness;183
8.1;6.1 Statistical Characterization of Seafloor Roughness;185
8.2;6.2 Measurement of Seafloor Roughness;188
8.3;6.3 Examples of Seafloor Roughness Spectra;194
8.4;6.4 Temporal Variability in Seafloor Roughness;196
8.5;6.5 Validity of Power-Law Assumption for Roughness Spectra;203
8.6;6.6 Relationships between Roughness and Sediment Physical Properties;205
8.7;6.7 Relationship between Spectral Parameters;207
8.8;6.8 Summary;209
8.9;6.9 Research Issues;210
9;7 Sediment Heterogeneity;213
9.1;7.1 Measurement of Heterogeneity;219
9.2;7.2 Statistical Characterization of Continuous Heterogeneity;234
9.3;7.3 Relationships Connecting Fluctuating Parameters;239
9.4;7.4 Measurement Bias Due to Finite Resolution;241
9.5;7.5 Examples of Heterogeneity Statistics;246
9.6;7.6 Research Issues;255
10;8 Fluid Theories;256
10.1;8.1 Equations of Motion;258
10.2;8.2 Plane Waves;259
10.3;8.3 Losses and Energy Flux;261
10.4;8.4 Boundary Conditions;264
10.5;8.5 Reflection and Transmission;265
10.6;8.6 Nonplane Waves, Flat Seafloors;270
10.7;8.7 Wood’s Equation;275
10.8;8.8 Research Issues;276
11;9 Elastic Theories;277
11.1;9.1 Equations of Motion;278
11.2;9.2 Plane Waves;279
11.3;9.3 Losses;281
11.4;9.4 Boundary Conditions;281
11.5;9.5 Reflection and Transmission;283
11.6;9.6 Nonplane Waves;286
11.7;9.7 Gassmann’s Equations;287
11.8;9.8 Buckingham’s Theory;288
11.9;9.9 Research Issues;293
12;10 Poroelastic Theories;294
12.1;10.1 Biot Theory;294
12.2;10.2 Effective Density Fluid Approximation;307
12.3;10.3 Experimental Tests of Biot Theory;311
12.4;10.4 Theoretical Alternatives;314
12.5;10.5 Research Issues;315
13;11 Reflection;317
13.1;11.1 Reflection Measurement Issues;318
13.2;11.2 Reflection Data Compared with Theory and Models;320
13.3;11.3 Research Issues;328
14;12 Seafloor Scattering Experiments;329
14.1;12.1 Monostatic Experiments;331
14.2;12.2 Bistatic Experiments;337
14.3;12.3 Research Issues;338
15;13 Roughness Scattering Models;339
15.1;13.1 General Properties of Roughness-Scattering Models;340
15.2;13.2 Small-Roughness Perturbation Approximation;346
15.3;13.3 Kirchhoff Approximation;361
15.4;13.4 Small-Slope Approximation;369
15.5;13.5 Composite-Roughness Approximation;370
15.6;13.6 Scattering by Discrete Features;376
15.7;13.7 Mathematical Accuracy of Approximations;377
15.8;13.8 Research Issues;384
16;14 Sediment Volume Scattering;385
16.1;14.1 Fluid Sediment Volume Scattering Models;386
16.2;14.2 Elastic Sediment Volume Scattering;409
16.3;14.3 Research Issues;414
17;15 Acoustic Penetration of the Seafloor;415
17.1;15.1 Roughness Perturbation Model;419
17.2;15.2 Mathematical Accuracy;427
17.3;15.3 Research Issues;427
18;16 Backscatter Statistics;429
18.1;16.1 General Statistical Properties of Backscattered Field;432
18.2;16.2 Gaussian Statistics;433
18.3;16.3 Non-Gaussian Statistics;438
18.4;16.4 Research Issues;450
19;A List of Symbols;451
20;B Calculation of Properties of Seawater;462
20.1;B.1 Seawater Density;463
20.2;B.2 Sound Speed in Seawater;465
20.3;B.3 Seawater Absorption and Attenuation;467
20.4;B.4 Seawater Viscosity;469
20.5;B.5 Electrical Conductivity of Seawater;472
20.6;B.6 Practical Salinity;475
21;C Coefficient of Variation of Sediment Parameters;477
22;D Roughness and Volume Statistics;480
22.1;D.1 Interface Roughness;480
22.2;D.2 Volume Heterogeneity;484
23;E Complex Representation of Signals;490
24;F Acoustic Transducers;492
25;G Acoustic Measurements;497
25.1;G.1 Reflection Measurements;497
25.2;G.2 Scattering Measurements;499
26;H Measurement Units and Decibels;513
27;I Causality Constraints on Speed–Attenuation Relations;515
28;J The Scattering Cross Section and Plane Waves;523
28.1;J.1 General Expressions;523
28.2;J.2 Far-Field Issues;527
29;K Rough-Interface Perturbation Theory;533
29.1;K.1 Fluid–Fluid Boundary;535
29.2;K.2 Fluid–Elastic Boundary;540
29.3;K.3 Fluid–Poroelastic Boundary;544
30;L The Kirchhoff and Small-Slope Approximations;545
30.1;L.1 Kirchhoff Approximation;545
30.2;L.2 Small-Slope Approximation;546
30.3;L.3 The Incoherent Reflection Coefficient;547
30.4;L.4 High-Frequency Limit of the Kirchhoff Approximation;549
31;M Volume Perturbation Theory;551
31.1;M.1 Fluid Sediment;551
31.2;M.2 Elastic Sediment;558
32;References;562
33;Index;607