Applied Underwater Acoustics - 1st Edition - Leif Bjørnø

Applied Underwater Acoustics - Leif Bjørnø

Description

Applied Underwater Acoustics meets the needs of scientists and engineers working in underwater acoustics and graduate students solving problems in, and preparing theses on, topics in underwater acoustics. The book is structured to provide the basis for rapidly assimilating the essential underwater acoustic knowledge base for practical application to daily research and analysis.

Each chapter of the book is self-supporting and focuses on a single topic and its relation to underwater acoustics. The chapters start with a brief description of the topic’s physical background, necessary definitions, and a short description of the applications, along with a roadmap to the chapter. The subtopics covered within individual subchapters include most frequently used equations that describe the topic. Equations are not derived, rather, assumptions behind equations and limitations on the applications of each equation are emphasized. Figures, tables, and illustrations related to the sub-topic are presented in an easy-to-use manner, and examples on the use of the equations, including appropriate figures and tables are also included. Key features

• Provides a complete and up-to-date treatment of all major subjects of underwater acoustics
• Presents chapters written by recognized experts in their individual field
• Covers the fundamental knowledge scientists and engineers need to solve problems in underwater acoustics
• Illuminates, in shorter sub-chapters, the modern applications of underwater acoustics that are described in worked examples
• Demands no prior knowledge of underwater acoustics, and the physical principles and mathematics are designed to be readily understood by scientists, engineers, and graduate students of underwater acoustics
• Includes a comprehensive list of literature references for each chapter

Table of contents Chapter 1. General Characteristics of the Underwater Environment 1.1. Introduction 1.2. A Brief Exposition of the History of Underwater Acoustics 1.3. International Standard Units 1.4. The Decibel Scales 1.5. Features of Oceanography 1.6. Sonar Equations 1.7 Abbreviations Chapter 2. Sound Propagation 2.1. The Concept of Waves 2.2. Sound Propagation in a Viscous Fluid 2.3. Sound Waves and Shear Waves in Marine Sediments 2.4. Source or Receiver in Motion 2.5. Sound Reflection and Transmission at a Fluid–Fluid Boundary 2.6. The “Ideal” Waveguide 2.7. The Pekeris Channel 2.8. Three-Dimensional Propagation Chapter 3. Sound Propagation Modeling 3.1. Ray Models 3.2. Wave Number Integration or Spectral Methods 3.3. Normal Mode Propagation Models 3.4. Parabolic Equation Methods 3.5. Finite-Difference and Finite-Element Methods 3.6. 3-D Sound Propagation Models List of Abbreviations and Symbols Chapter 4. Absorption of Sound in Seawater 4.1. Physics and Phenomena 4.2. Experimental Data 4.3. Sound Absorption Mechanisms 4.4. Formulas and Expressions 4.5. Symbols and Abbreviations Chapter 5. Scattering of Sound 5.1. Physics and Phenomena 5.2. Scattering From Point-Like Objects 5.3. Scattering From Extended, Nearly Plane, Rough Surfaces 5.4. Theoretical Basis for Scattering Calculations 5.5. Scattering From Curved, Rough Surfaces 5.6. Reverberation 5.7. Symbols and Abbreviations Chapter 6. Ambient Noise 6.1. Physics and Phenomena 6.2. Sources of Ambient Noise 6.3. Spectra of Ambient Noise 6.4. Directivity of Ambient Noise 6.5. Coherence of Ambient Noise 6.6. Self-Noise 6.7. Amplitude Distributions for Underwater Noise 6.8. Symbols and Abbreviations Chapter 7. Shallow-Water Acoustics 7.1. What Is Shallow-Water Acoustics? 7.2. Physics and Phenomena 7.3. Some Additional Topics of Interest in Shallow-Water Acoustics 7.4. Some Newer Topics List of Acronyms List of Symbols in Equations Chapter 8. The Seafloor 8.1. Background and History 8.2. The Origin and Nature of Seafloor Sediments 8.3. Acoustics of Sediments 8.4. Model for Sound Scattering by the Seafloor 8.5. Sediment Physical Properties 8.6. Sediment Geoacoustic Properties 8.7. Seafloor Roughness 8.8. Seafloor Heterogeneity 8.9. Seafloor Identification and Characterization by Use of Sonar List of Symbols Chapter 9. Inverse Methods in Underwater Acoustics 9.1. Introduction 9.2. Some Basic Mathematical Relationships 9.3. Source Localization by Matched Field Processing 9.4. Geoacoustic Inversion 9.5. Ocean Acoustic Tomography Chapter 10. Sonar Systems 10.1. Sonar System Applications 10.2. Sonar System Types 10.3. Single-Beam Echo Sounders 10.4. Multibeam Echo Sounders 10.5. Side-Scan Sonar 10.6. Synthetic Aperture Sonar 10.7. Other Sonar Types 10.8. Transducer Calibration 10.9. Sonar System Example Calculations 10.10. Sonar Design Calculations 10.11. Symbols and Abbreviations Chapter 11. Signal Processing 11.1. Background and Definitions 11.2. Characterizing the Signal and Noise 11.3. Filtering 11.4. Detection 11.5. Estimation Chapter 12. Bio- and Fishery Acoustics 12.1. Introduction 12.2. Marine Life: From Whales to Plankton 12.3. Acoustic Scattering by Marine Life 12.4. Active Imaging Systems 12.5. Marine Life and Sound 12.6. Passive Acoustic Monitoring 12.7. Selected Practical Applications 12.8. Conclusions: Future Developments Chapter 13. Finite-Amplitude Waves 13.1. Physics and Nonlinear Phenomena 13.2. Nonlinear Underwater Acoustics 13.3. Underwater Explosions 13.4. List of Symbols and Abbreviations Chapter 14. Underwater Acoustic Measurements and Their Applications 14.1. Introduction 14.2. Acoustics and Marine Renewable Energy Developments 14.3. Underwater Acoustics in Nuclear-Test-Ban Treaty Monitoring 14.4. Characterization of Noise From Ships 14.5. Underwater Soundscapes 14.6. Underwater Acoustic Communications 14.7. Underwater Archaeology 14.8. Applications of Underwater Acoustics in Polar Environments 14.9. Tank Experiments 14.10. Acoustic Positioning at Sea 14.11. Ocean Observing Systems and Ocean Observatories, Oceanographers, and Acousticians—A Personal Perspective 14.12. Applications of Underwater Acoustics to Military Purposes