The Handbook of Sidescan Sonar (Springer Praxis Books Geophysical Sciences)

Sidescan sonar is proving to be the preeminent technique for researchers and professionals seeking knowledge about the structure and behavior of the seafloor, but its data is often difficult to interpret due to the physics of acoustic remote sensing, and to the varied geological processes at play. This book covers the fundamentals of sidescan sonar, incorporates new understanding of marine structures, and explains how to interpret sidescan sonar imagery and bathymetry.. Springer 3540426418 1 Title Page 3 Copyright Page 4 Table of Contents 5 Preface 10 Acknowledgments 12 Figures 14 Tables 21 Abbreviations and acronyms 22 1 Introduction 26 1.1 Book overview 26 2 Acoustic signals and data aquisition 32 2.1 Sonar mapping systems 32 2.2 Acoustic theory; basics 34 2.2.1 Acoustic waves 34 2.2.2 Acoustic propagation 35 2.2.3 Acoustic scattering; theory 40 2.3 Signal generation and data acquisition 43 2.3.1 Acoustic Projectors 43 2.3.2 Hydrophones and arrays 46 2.3.3 Signal conditioning 46 2.4 New concepts; new tools 48 2.4.1 Higher frequencies; higher resolutions 48 2.4.2 Multistatic sonars 49 2.4.3 Synthetic aperture sonar 50 2.4.4 Parametric sidescan sonar 52 2.4.5 Biomimetics 54 2.5 Sonar performance 55 2.6 Conclusion 57 2.7 Further reading 58 3 Imagery and bathymetry 60 3.1 Processing acoustic measurements 60 3.2 Sidescan sonar imagery 62 3.2.1 Slant range and ground rage 62 3.2.2 Backscatter stregth 63 3.3 Adding bathymetry 65 3.3.1 Sidescan bathymetry and interferometry 65 3.3.2 Multibeam bathymetry 68 3.4 Merging imagery and bathymetry 68 3.5 Conclusion 71 3.6 Further reading 71 4 Sidescan sonar data processing 73 4.1 Backscatter profiles 73 4.2 Navigation and attitude 74 4.2.1 Navigation of surface vehicles 74 4.2.2 Navigation of underwater vehicles 76 4.2.3 Attitude information 80 4.3 Pre-processing 81 4.3.1 Definations 81 4.3.2 Data formats 81 4.3.3 Navigation pre-processing 82 4.3.4 Attitude pre-processing 85 4.4 Radiometric corrections 86 4.4.1 Requantization 86 4.4.2 Across-track corrections 87 4.4.3 Along-track corrections 87 4.5 Geometric corrections 89 4.5.1 Slant-range correction 89 4.5.2 Anamorphosis 90 4.6 Bathymetry processing 91 4.7 Map production 92 4.7.1 Mosaicking/Stenciling 92 4.7.2 Interpolation/Rubbersheeting 92 4.8 Post-processing 93 4.8.1 Image statistics 93 4.8.2 Histogram manipulations 94 4.8.3 Speckle removal 97 4.8.4 Sea surface reflection removal 98 4.9 Operational examples 99 4.10 Interpretation of sonar images 101 4.11 Conclusion 106 4.12 Further reading 107 5 Spreading and subduction 109 5.1 Plate tectonics and the seafloor 109 5.2 Tectonic structures 113 5.3 Volcanic structures 118 5.4 Sedimented areas 126 5.5 Hydrothermal structures 127 5.6 Seafloor structures associated with subduction 130 5.7 Examples of regional imagery 136 5.8 Conclusions 138 5.9 Further reading 140 6 Abyssal basins and the polar seas 141 6.1 Introduction 141 6.2 Using ancillary information 142 6.2.1 Other acoustic tools 142 6.2.2 Non-acoustic remote sensing 144 6.2.3 Direct sampling 146 6.3 Abyssal basins 146 6.3.1 Geological background 146 6.3.2 Sediment input 148 6.3.3 Relict structures 152 6.3.4 Sedimentary structures 153 6.4 Polar seas 157 6.4.1 General setting 157 6.4.2 Ice-related structures 159 6.4.3 Other typical structures 161 6.5 Regional imagery: the Hawaiian Abyssal Plain 162 6.6 Conclusion 167 6.7 Further reading 168 7 Continental margins 170 7.1 Introduction 170 7.2 Sedimentary structures 172 7.2.1 Sediment deposition and erosion 172 7.2.2 Sediment transport—submarine canyons 174 7.2.3 Mass-wasting, slides, and flows 182 7.2.4 Sediment redistribution 184 7.3 Tectonic and volcanic structures 188 7.4 Other structures 191 7.4.1 Biological activity—past and present 191 7.4.2 Fluid and gas seepage structures 195 7.4.3 Brine pools 199 7.5 Regional imagery 200 7.5.1 The Blake Escarpment, North Atlantic 200 7.5.2 The Almería Canyon and Almería Margin, Mediterranean Sea 202 7.6 Conclusions 205 7.7 Further reading 206 8 Shallow-water environments 207 8.1 Introduction 207 8.2 Sedimentary structures 208 8.3 Rock outcrops 212 8.4 Biological stucutures 216 8.5 Regional imagery 218 8.6 Conclusion 221 8.7 Further reading 221 9 Man-made structures 222 9.1 Introduction 222 9.2 Planned structures 222 9.2.1 Pipelines—cables 222 9.2.2 Dump sites 225 9.2.3 Harbor areas 227 9.2.4 Seabed resources and their exploitation 228 9.3 Accidental structures 229 9.3.1 Fishing activities 229 9.3.2 Shipwrecks 232 9.3.3 Pollution 236 9.4 Seabed waste and military mines 238 9.4.1 Seabed waste 238 9.4.2 Military mines 239 9.5 Sonars and underwater archeology 241 9.6 Conclusion 242 9.7 Further reading 243 10 Anomalies and artifacts 244 10.1 Introduction 244 10.2 Propagation artifacts 245 10.2.1 Water column variations 245 10.2.2 Beam spreading 247 10.2.3 Acoustic noise 248 10.3 Physical (scattering) artifacts 248 10.3.1 Sub-surface reflections 248 10.3.2 Multipath scattering 249 10.3.3 Unexpected features 254 10.4 Processing artifacts 256 10.4.1 Radiometric artifacts 256 10.4.2 Geometric artifacts 258 10.4.3 Slant-range correction—layover 264 10.4.4 Identifying the origin of artifacts 265 10.5 Interpretation of artifacts 267 10.5.1 Output/display artifacts 267 10.5.2 Unexpected features 268 10.6 Conclusion 268 10.7 Further reading 269 11 Computer-assisted interpretation 270 11.1 Inroduction 270 11.2 Traditional techniques 271 11.2.1 Image enhancement 271 11.2.2 Contour-oriented analyses 276 11.2.3 Texture-oriented analyses 283 11.3 New techniques 285 11.3.1 Data Fusion and Geographic Information Systems 285 11.3.2 Neural networks and genetic algorithms 289 11.3.3 Image compression 291 11.4 Seabed characterization 291 11.4.1 Goals, purposes, limits 291 11.4.2 Applications 293 11.5 Artificial Intelligence—expert systems 295 11.6 Conclusion 296 11.7 Further reading 296 12 Conclusion 298 References 300 Index 333 "ISBN-13:,9783540426417" ISBN-13: 9783540426417

seafloor Surveying With Acoustic Remote Sensing Has Become A Powerful Tool For Researchers And Professionals Seeking Knowledge About The Structure And Behavior Of The Seafloor. In Particular, Sidescan Sonar Is Proving To Be The Preeminent Technique, But Its Data Is Often Difficult To Interpret Due To The Physics Of Acoustic Remote Sensing, And To The Varied Geological Processes At Play. This Handbook Not Only Presents All The Fundamentals But Also Explains How To Interpret Sidescan Sonar Imagery And Bathymetry. It Fully Explores The Most Recent Advances, Both In The Technology And In The Knowledge Of Marine Structures, And Provides Deep Insights For Interpretation And Decision-making. Broadly Expanded And Updated From The Previous 1997 “handbook Of Seafloor Sonar Imagery”, This Handbook Is Indispensable To Oceanographers, Resource Exploiters, Telecommunications Engineers, And Marine Researchers Of All Kinds.