Underwater Acoustic Modelling and Simulation, Third Edition

Underwater Acoustic Modeling and Simulation examines the translation of our physical understanding of sound in the sea into mathematical models that can simulate acoustic propagation, noise and reverberation in the ocean. These models are used in a variety of research and operational applications to predict and diagnose the performance of complex sonar systems operating in the undersea environment. Previous editions of the book have provided invaluable guidance to sonar technologists, acoustical oceanographers and applied mathematicians in the selection and application of underwater acoustic models. Now that simulation is fast becoming an accurate, efficient and economical alternative to field-testing and at-sea training, this new edition will also provide useful guidance to systems engineers and operations analysts interested in simulating sonar performance. Guidelines for selecting and using available propagation, noise and reverberation models are highlighted. Specific examples of each type of model are discussed to illustrate model formulations, assumptions and algorithm efficiency. Instructive case studies demonstrate applications in sonar simulation. Book Cover......Page 1 Title......Page 4 Contents......Page 5 Preface......Page 16 Preface to the second edition......Page 18 Preface to the first edition......Page 20 Acknowledgments......Page 22 Introduction......Page 24 Framework......Page 25 Measurements and prediction......Page 27 Developments in modeling......Page 29 Advances in simulation......Page 32 Operational challenges......Page 33 Naval operations......Page 34 Offshore industries......Page 36 Operational oceanography......Page 37 Inverse acoustic sensing of the oceans......Page 38 Standard definitions......Page 40 Acoustical oceanography......Page 42 Temperature distribution......Page 44 Salinity distribution......Page 45 Sound speed......Page 48 Sound-speed distribution......Page 51 Boundaries......Page 58 Ice cover......Page 61 Sea floor......Page 62 Dynamic features......Page 66 Mesoscale features......Page 67 Fine-scale features......Page 77 Biologics......Page 78 Propagation I: observations and physical models......Page 80 Nature of measurements......Page 81 Basic concepts......Page 82 Sea-surface boundary......Page 88 Forward scattering and reflection loss......Page 89 Image interference and frequency effects......Page 90 Turbidity and bubbles......Page 92 Ice interaction......Page 93 Measurements......Page 95 Forward scattering and reflection loss......Page 96 Interference and frequency effects......Page 101 Measurements......Page 102 Attenuation and absorption in sea water......Page 103 Surface ducts......Page 105 General propagation features......Page 108 Low-frequency cutoff......Page 111 Deep-sound channel......Page 114 Convergence zones......Page 116 Reliable acoustic path......Page 117 Arctic half-channel......Page 118 Coherence......Page 120 Propagation II: mathematical models (Part One)......Page 122 Theoretical basis for propagation modeling......Page 123 Classification of modeling techniques......Page 125 Ray-theory models......Page 126 Caustics......Page 129 Gaussian beam tracing......Page 130 Arrival structure......Page 132 Beam displacement......Page 134 Normal-mode models......Page 136 Normal-mode solution......Page 137 Dispersion effects......Page 139 Experimental measurements......Page 140 Range dependence......Page 141 High-frequency adaptations......Page 143 Multipath expansion models......Page 144 Fast-field models......Page 145 Parabolic equation models......Page 146 Basic theory......Page 147 Numerical techniques......Page 149 Wide-angle and 3D adaptations......Page 152 High-frequency adaptations......Page 153 The RAYMODE model a specific example......Page 154 Numerical model summaries......Page 158 Propagation II: mathematical models (Part Two)......Page 175 Wave-theory models......Page 177 Oceanographic mixed-layer models......Page 178 Shallow-water duct models......Page 181 Optimum frequency of propagation......Page 182 Numerical models......Page 185 Empirical models......Page 190 Arctic models......Page 195 Numerical models......Page 196 Empirical models......Page 197 Data support requirements......Page 199 Sound-speed profile synthesis......Page 200 Earth curvature corrections......Page 202 Merging techniques......Page 203 Stochastic modeling......Page 204 Broadband modeling......Page 205 Matched field processing......Page 206 Transmutation approaches......Page 208 Chaos......Page 209 Three-dimensional modeling......Page 210 Ocean fronts, eddies and internal waves......Page 211 Coupled ocean acoustic modeling......Page 216 Acoustic tomography......Page 217 Phase conjugation and time-reversal mirrors......Page 221 Noise I: observations and physical models......Page 223 Seismo-acoustic noise......Page 225 Shipping noise......Page 226 Bioacoustic noise......Page 228 Depth dependence......Page 232 Arctic ambient noise......Page 233 Acoustic daylight......Page 234 Geoacoustic inversion......Page 235 Noise II: mathematical models......Page 237 Ambient-noise models......Page 239 The RANDI model a specific example......Page 242 Recent developments......Page 244 The noise notch......Page 245 Beam-noise statistics models......Page 248 Data support requirements......Page 249 Numerical model summaries......Page 252 Reverberation I: observations and physical models......Page 255 Volume reverberation......Page 256 Deep scattering layer......Page 257 Vertical-scattering plumes......Page 258 Boundary reverberation......Page 259 Under-ice reverberation......Page 263 Inversion techniques......Page 266 Reverberation II: mathematical models......Page 267 Advanced developments......Page 270 Cell-scattering models......Page 271 Boundary-reverberation theory......Page 273 The REVMOD model a specific example......Page 274 Bistatic reverberation......Page 278 The bistatic acoustic model a specific example......Page 280 Point-scattering models......Page 282 The under-ice reverberation simulation model a specific example......Page 283 Numerical model summaries......Page 284 Sonar performance models......Page 287 Sonar equations......Page 288 The NISSM model a specific example......Page 293 Propagation......Page 294 Reverberation......Page 296 Target echo......Page 298 Signal-to-noise ratio......Page 299 Probability of detection......Page 300 Model operating systems......Page 304 System architecture......Page 305 Sonar modeling functions......Page 306 System usage......Page 309 The comprehensive acoustic system simulation a specific example......Page 310 Data sources and availability......Page 311 Numerical model summaries......Page 315 Model evaluation......Page 319 Past evaluation efforts......Page 320 Analytical benchmark solutions......Page 321 Quantitative accuracy assessments......Page 324 The POSSM experience a specific example......Page 325 Evaluation guidelines......Page 328 Verification......Page 330 Validity......Page 331 Usability......Page 332 Simulation......Page 336 Hierarchical levels......Page 337 Engineering......Page 338 Mission......Page 339 High-level architecture......Page 340 Testbeds......Page 341 Applications......Page 342 Systems engineering......Page 343 Operations analysis......Page 348 Training......Page 349 Abbreviations and acronyms......Page 351 Glossary of terms......Page 365 Websites......Page 374 References......Page 377 Author index......Page 426 Subject index......Page 438 Underwater acoustics entails the development and employment of acoustical methods to image underwater features, to communicate information via the oceanic waveguide or to measure oceanic properties.