Sound propagation through the stochastic ocean:
Gespeichert in:
1. Verfasser: | |
---|---|
Format: | Buch |
Sprache: | English |
Veröffentlicht: |
New York, NY
Cambridge University Press
2016
|
Schlagworte: | |
Online-Zugang: | Inhaltsverzeichnis Klappentext |
Beschreibung: | Includes bibliographical references and index |
Beschreibung: | xxi, 420 pages |
ISBN: | 9781107072343 |
Internformat
MARC
LEADER | 00000nam a2200000 c 4500 | ||
---|---|---|---|
001 | BV043722385 | ||
003 | DE-604 | ||
005 | 20170421 | ||
007 | t | ||
008 | 160817s2016 xxu |||| 00||| eng d | ||
010 | |a 016008185 | ||
020 | |a 9781107072343 |9 978-1-107-07234-3 | ||
035 | |a (OCoLC)992495988 | ||
035 | |a (DE-599)BVBBV043722385 | ||
040 | |a DE-604 |b ger |e rda | ||
041 | 0 | |a eng | |
044 | |a xxu |c US | ||
049 | |a DE-703 | ||
050 | 0 | |a QC242.2 | |
082 | 0 | |a 620.2/5 |2 23 | |
084 | |a UF 6200 |0 (DE-625)145599: |2 rvk | ||
100 | 1 | |a Colosi, John A. |e Verfasser |4 aut | |
245 | 1 | 0 | |a Sound propagation through the stochastic ocean |c John A. Colosi, Naval Postgraduate School |
264 | 1 | |a New York, NY |b Cambridge University Press |c 2016 | |
300 | |a xxi, 420 pages | ||
336 | |b txt |2 rdacontent | ||
337 | |b n |2 rdamedia | ||
338 | |b nc |2 rdacarrier | ||
500 | |a Includes bibliographical references and index | ||
650 | 4 | |a Underwater acoustics | |
650 | 4 | |a Sound |x Transmission | |
650 | 4 | |a Oceanography | |
650 | 0 | 7 | |a Hydroakustik |0 (DE-588)4259255-0 |2 gnd |9 rswk-swf |
650 | 0 | 7 | |a Meer |0 (DE-588)4038301-5 |2 gnd |9 rswk-swf |
650 | 0 | 7 | |a Schallausbreitung |0 (DE-588)4179359-6 |2 gnd |9 rswk-swf |
689 | 0 | 0 | |a Schallausbreitung |0 (DE-588)4179359-6 |D s |
689 | 0 | 1 | |a Meer |0 (DE-588)4038301-5 |D s |
689 | 0 | 2 | |a Hydroakustik |0 (DE-588)4259255-0 |D s |
689 | 0 | |5 DE-604 | |
856 | 4 | 2 | |m Digitalisierung UB Bayreuth - ADAM Catalogue Enrichment |q application/pdf |u http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&local_base=BVB01&doc_number=029134433&sequence=000003&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA |3 Inhaltsverzeichnis |
856 | 4 | 2 | |m Digitalisierung UB Bayreuth - ADAM Catalogue Enrichment |q application/pdf |u http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&local_base=BVB01&doc_number=029134433&sequence=000004&line_number=0002&func_code=DB_RECORDS&service_type=MEDIA |3 Klappentext |
999 | |a oai:aleph.bib-bvb.de:BVB01-029134433 |
Datensatz im Suchindex
_version_ | 1804176515412262912 |
---|---|
adam_text | Contents
Foreword page xiii
Preface xv
Notation xix
PARTI INTRODUCTION AND PREREQUISITES
1 Sound Propagation through the Stochastic Ocean 3
1.1 Introduction and Historical Background 3
1.1.1 Ocean Dynamics and Fluctuations 6
1.1.2 Theory of Sound Propagation 12
1.2 Three Decades of Development: Observations 14
1.2.1 Deep Water 14
1.2.2 Emergence of Shallow-Water Acoustics 21
1.2.3 Ocean Sound-Speed Spectrum 24
1.3 Three Decades of Development: Theory 25
1.3.1 Ray Theory 28
1.3.2 Weak Fluctuation Theory 30
1.3.3 Path Integral Theory 32
1.3.4 Coupled-Mode Transport Theory 34
1.4 Where We Stand 36
1.5 Utilizing this Book 37
2 Acoustical Prerequisites 40
2.1 Introduction 40
2.2 Fundamental Equations of Hydrodynamics 40
2.2.1 Parabolic Wave Equation 42
2.3 Character of the Oceanic Acoustic Waveguide 43
2.3.1 Canonical Sound-Speed Profiles 45
2.3.2 Sound-Speed Fluctuations due to Internal Waves 47
vii
Contents
viii
23.3 Example Profiles 47
23.4 Attenuation of Sound 49
2.4 Rays 52
2.4.1 Physical Picture and Basic Equations 52
2.4.2 Ray Theory: Asymptotic Analysis 55
2.4.3 Ray Amplitude and Stability 56
2.4.4 Ray Chaos: Introduction 59
2.4.5 Ehrenfest Theorem 61
2.4.6 Rays in a Range-Independent Ocean 63
2.5 Fresnel Zones and Ray Tubes 70
2.6 Bom and Rytov Approximations 75
2.6.1 Relation to Amplitude and Phase 77
2.6.2 Relationship between Born and Rytov Solutions 77
2.7 Path Integrals 78
2.7.1 Variational Approach to Ray Propagation 78
2.7.2 Path Integrals: A Qualitative Discussion 80
2.7.3 Formulation of the Path integral 80
2.7.4 Solution of the Parabolic Equation as a Path Integral 81
2.8 Normal Modes 82
2.8.1 Coupled Mode Equations 83
2.8.2 Adiabatic Theory 86
2.8.3 Vertical Modes, Horizontal Rays 87
2.8.4 Modes in a Range-Independent Ocean 88
Appendix A Green’s Functions and the Fresnel Zone 100
Appendix B WKB Modes 102
3 Stochastic Ocean Internal Waves 104
3.1 Introduction 104
3.2 Fundamental Equations of Hydrodynamics 108
3.2.1 Ray Theory: Local Plane Waves 109
3.2.2 Modal Solutions 113
3.23 WKB Analysis 115
3.3 Garrett-Munk Internal-Wave Model 118
33.1 Other Useful Forms of the GM Spectrum 121
3.3.2 Maximum Internal-Wave Mode Number 123
333 Internal-Wave Correlation Scales 124
33.4 Modifications to GM 126
3.4 Observations 127
3.4.1 Deep Ocean: Mid-Latitude 128
3.4.2 Seamounts, Slopes, and Canyons 131
3.4.3 Continental Shelves 131
Contents ix
3.4.4 Arctic and High Latitude 133
3.4.5 Equator 134
3.5 Other Sources of Stochastic Sound-Speed Structure 135
3.5.1 Spice 136
3.5.2 Vortical Motions 139
Appendix A An Internal-Wave Model with an Exponential Correlation
Function 139
Appendix B Monte Carlo Simulation 141
4 Introduction to Acoustic Fluctuations 144
4.1 Origin of Phase and Amplitude Fluctuations 144
4.1.1 Weak Fluctuations 145
4.1.2 Strong Fluctuations: Wave Front Folding and Interference 145
4.1.3 Ray Micro-multipath 147
4.1.4 A Simple Model of Microray Interference 153
4.1.5 Modal-multipath: Mode Coupling 156
4.2 Acoustic Sensitivity to Internal Waves 157
4.2.1 Ray/Internal Wave Resonance and Diffraction 159
4.2.2 Ray Chaos 165
4.2.3 Mode Coupling 167
4.3 Propagation Regimes and Signal Behavior 169
4.3.1 Definition of O and A: Ray Propagation 170
4.3.2 Acoustic Behavior in Different A - D Regimes 175
4.3.3 Coherence Functions 181
PART II WAVE PROPAGATION THEORIES
5 Ray Theory 187
5.1 Introduction 187
5.2 Fundamental Equations: Displacement and Current 189
5.3 Travel-Time Variance 192
5.3.1 Ray-Tangent Approximation 195
5.3.2 Accuracy of Ray-Tangent Approximation 198
5.3.3 Observations 200
5.4 Other Ray-like Observables 202
5.4.1 Ray-Angle Variance 202
5.4.2 Ray-Intensity Variance 204
5.5 Scattering Along and Across the Wave Front 206
5.6 Ray Chaos 208
5.6.1 Nonlinear Response to Forcing 209
5.6.2 Features of Chaos and KAM Theory 212
5.6.3 Levels of Randomness: Ray Statistics 215
X
Contents
5.7 The a Parameter 216
5.7.1 Action Angle Variables Revisited 217
5.7.2 Ray Stability 219
5.7.3 Travel-Time Stability 221
5.8 Travel-Time Statistics: Random Walk Model 222
5.8.1 Eigenray Constrained Model 224
5.8.2 Unconstrained Model 225
5.9 Ray Chaos in Observations 226
5.9.1 Nature of Chaotic Rays and Time Fronts 226
5.9.2 Acoustic Field Statistics 231
5.10 Wave Chaos 235
5.11 Summary 237
Appendix A Calculation of dz/d9 in a Waveguide 239
6 Weak Fluctuation Theory 241
6.1 Introduction 241
6.2 Spectra of Phase and Log-Amplitude: No Waveguide 242
6.2.1 Incident Plane Wave 242
6.2.2 Point Source 246
6.3 Spectra of Phase and Log-Amplitude: Ocean Waveguide 247
6.3.1 Local Straight Ray Approximation 247
6.3.2 A More Rigorous Approach 248
6.3.3 Depth/Time Observation Plane 252
6.3.4 Variances of Phase and Log-Amplitude 253
6.3.5 An Example Calculation 254
6.4 A - O Revisited 256
6.4.1 Spectral Average, {m2} 257
6.4.2 Fresnel Zone 257
6.4.3 Border of the Unsaturated Regime 259
6.5 Observations 260
6.5.1 Cobb Seamount and MATE 261
6.5.2 AFAR 265
6.5.3 AATE 267
6.5.4 AET-87 268
6.6 Summary 270
7 Path Integral Theory 271
7.1 Introduction 271
7.2 Path Integral Theory 273
7.2.1 A Simple Example 275
7.2.2 A Note on the PE Approximation 276
Mean Pressure 277
7.3
Contents xi
7.4 Mutual Coherence Functions: Space and Time Separations 278
7.4.1 A Broadband Microray Coherence Theory 281
7.4.2 Evaluation of Phase Structure Function 282
7.4.3 Depth Separations 284
7.4.4 Time Separations 285
7.4.5 Horizontal Separations 286
7.4.6 Relation to Signals with Multiple Deterministic Paths 287
7.4.7 Observations: Single Path 288
7.4.8 Observations: Multiple Paths, Long Range, and Shallow Water 292
7.4.9 Internal-Wave Tomography 300
7.5 Mutual Coherence Functions: Frequency Separations 303
7.5.1 Evaluation of Q(Aq) 307
7.5.2 Observations 310
7.6 Time-Lagged Intensity Covariance 312
7.6.1 Observations 313
7.7 Intensity Coherence and Spectra 314
7.7.1 Separations in Time 318
7.7.2 Separations in Depth 320
7.7.3 Separations in Frequency 321
7.7.4 Observations 321
7.8 Intensity Moments: Microray Focusing Parameter 323
7.8.1 Observations 328
7.9 Summary - 329
Appendix A Path Integrals as Products of Delta Functions 329
Appendix B Solution of the Gaussian Path Integral for Frequency
Correlations 330
Appendix C GM Spectral Averages for Path Integral Equations 331
Mode Transport Theory 333
8.1 Introduction 333
8.2 Solutions to the Coupled Mode Equation 335
8.2.1 Adiabatic Solution 338
8.3 Coupling Matrix Correlation Function 338
8.3.1 Scattering Matrix 340
8.4 Mean Pressure 341
8.4.1 Adiabatic Theory 342
8.4.2 Transport Theory 342
8.4.3 Solution for Mean Pressure 344
8.4.4 Connection between Transport and Adiabatic Theory 345
8.5 Mean Intensity 346
8.5.1 Adiabatic Theory 346
Contents
xii
8.5.2 Transport Theory 347
8.5.3 Mode Energy 349
8.5.4 Two-Mode Example 352
8.5.5 Hybrid Theory 354
8.5.6 Monte Carlo Validation 355
8.5.7 Observations 360
8.6 Mutual Coherence Functions: Space and Time Separations 365
8.6.1 Depth Separations 368
8.6.2 Temporal Separations 371
8.6.3 Transverse Separations 373
8.6.4 Observations 376
8.7 Mutual Coherence Function: Frequency Separations 382
8.7.1 Adiabatic Approach 384
8.7.2 Effects of Coupling 385
8.8 Intensity Variance 387
8.8.1 Adiabatic Approach and Hybrid Theory 390
8.8.2 Transport Theory 391
8.8.3 Asymptotic Behavior 391
8.8.4 Two-Mode Example 394
8.8.5 Observations 397
8.9 Summary 399
Appendix A Integrals Related to Standard Scattering Matrices 399
Appendix B Integrals Related to MCFs witn Temporal and Transverse Lags 400
Appendix C Random Surface Gravity Waves 401
References
Index
403
417
The ocean is opaque to electromagnetic radiation and transparent to low-
frequency sound. So acoustical methodologies are an important tool for sensing
the undersea world. Stochastic sound-speed fluctuations in the ocean, such as
those caused by internal waves, result in a progressive randomization of acoustic
signals as they traverse the ocean environment. This signal randomization imposes
a limit to the effectiveness of ocean acoustic remote sensing, navigation and
communication. At the same time, signal fluctuations can be used as an important
probe to better understand stochastic ocean processes.
Sound Propagation through the Stochastic Ocean provides a comprehensive
treatment of developments in the field of statistical ocean acoustics over the last
thirty-five years. This book will be of fundamental interest to oceanographers,
marine biologists, geophysicists, engineers, applied mathematicians, and
physicists. Key discoveries in topics such as internal waves, ray chaos, Feynman
path integrals, and mode transport theory are addressed with illustrations from
ocean observations. The topics are presented at an approachable level for advanced
students and seasoned researchers alike.
ISBN 978-1-107-07234-3
|
any_adam_object | 1 |
author | Colosi, John A. |
author_facet | Colosi, John A. |
author_role | aut |
author_sort | Colosi, John A. |
author_variant | j a c ja jac |
building | Verbundindex |
bvnumber | BV043722385 |
callnumber-first | Q - Science |
callnumber-label | QC242 |
callnumber-raw | QC242.2 |
callnumber-search | QC242.2 |
callnumber-sort | QC 3242.2 |
callnumber-subject | QC - Physics |
classification_rvk | UF 6200 |
ctrlnum | (OCoLC)992495988 (DE-599)BVBBV043722385 |
dewey-full | 620.2/5 |
dewey-hundreds | 600 - Technology (Applied sciences) |
dewey-ones | 620 - Engineering and allied operations |
dewey-raw | 620.2/5 |
dewey-search | 620.2/5 |
dewey-sort | 3620.2 15 |
dewey-tens | 620 - Engineering and allied operations |
discipline | Physik |
format | Book |
fullrecord | <?xml version="1.0" encoding="UTF-8"?><collection xmlns="http://www.loc.gov/MARC21/slim"><record><leader>01982nam a2200469 c 4500</leader><controlfield tag="001">BV043722385</controlfield><controlfield tag="003">DE-604</controlfield><controlfield tag="005">20170421 </controlfield><controlfield tag="007">t</controlfield><controlfield tag="008">160817s2016 xxu |||| 00||| eng d</controlfield><datafield tag="010" ind1=" " ind2=" "><subfield code="a">016008185</subfield></datafield><datafield tag="020" ind1=" " ind2=" "><subfield code="a">9781107072343</subfield><subfield code="9">978-1-107-07234-3</subfield></datafield><datafield tag="035" ind1=" " ind2=" "><subfield code="a">(OCoLC)992495988</subfield></datafield><datafield tag="035" ind1=" " ind2=" "><subfield code="a">(DE-599)BVBBV043722385</subfield></datafield><datafield tag="040" ind1=" " ind2=" "><subfield code="a">DE-604</subfield><subfield code="b">ger</subfield><subfield code="e">rda</subfield></datafield><datafield tag="041" ind1="0" ind2=" "><subfield code="a">eng</subfield></datafield><datafield tag="044" ind1=" " ind2=" "><subfield code="a">xxu</subfield><subfield code="c">US</subfield></datafield><datafield tag="049" ind1=" " ind2=" "><subfield code="a">DE-703</subfield></datafield><datafield tag="050" ind1=" " ind2="0"><subfield code="a">QC242.2</subfield></datafield><datafield tag="082" ind1="0" ind2=" "><subfield code="a">620.2/5</subfield><subfield code="2">23</subfield></datafield><datafield tag="084" ind1=" " ind2=" "><subfield code="a">UF 6200</subfield><subfield code="0">(DE-625)145599:</subfield><subfield code="2">rvk</subfield></datafield><datafield tag="100" ind1="1" ind2=" "><subfield code="a">Colosi, John A.</subfield><subfield code="e">Verfasser</subfield><subfield code="4">aut</subfield></datafield><datafield tag="245" ind1="1" ind2="0"><subfield code="a">Sound propagation through the stochastic ocean</subfield><subfield code="c">John A. Colosi, Naval Postgraduate School</subfield></datafield><datafield tag="264" ind1=" " ind2="1"><subfield code="a">New York, NY</subfield><subfield code="b">Cambridge University Press</subfield><subfield code="c">2016</subfield></datafield><datafield tag="300" ind1=" " ind2=" "><subfield code="a">xxi, 420 pages</subfield></datafield><datafield tag="336" ind1=" " ind2=" "><subfield code="b">txt</subfield><subfield code="2">rdacontent</subfield></datafield><datafield tag="337" ind1=" " ind2=" "><subfield code="b">n</subfield><subfield code="2">rdamedia</subfield></datafield><datafield tag="338" ind1=" " ind2=" "><subfield code="b">nc</subfield><subfield code="2">rdacarrier</subfield></datafield><datafield tag="500" ind1=" " ind2=" "><subfield code="a">Includes bibliographical references and index</subfield></datafield><datafield tag="650" ind1=" " ind2="4"><subfield code="a">Underwater acoustics</subfield></datafield><datafield tag="650" ind1=" " ind2="4"><subfield code="a">Sound</subfield><subfield code="x">Transmission</subfield></datafield><datafield tag="650" ind1=" " ind2="4"><subfield code="a">Oceanography</subfield></datafield><datafield tag="650" ind1="0" ind2="7"><subfield code="a">Hydroakustik</subfield><subfield code="0">(DE-588)4259255-0</subfield><subfield code="2">gnd</subfield><subfield code="9">rswk-swf</subfield></datafield><datafield tag="650" ind1="0" ind2="7"><subfield code="a">Meer</subfield><subfield code="0">(DE-588)4038301-5</subfield><subfield code="2">gnd</subfield><subfield code="9">rswk-swf</subfield></datafield><datafield tag="650" ind1="0" ind2="7"><subfield code="a">Schallausbreitung</subfield><subfield code="0">(DE-588)4179359-6</subfield><subfield code="2">gnd</subfield><subfield code="9">rswk-swf</subfield></datafield><datafield tag="689" ind1="0" ind2="0"><subfield code="a">Schallausbreitung</subfield><subfield code="0">(DE-588)4179359-6</subfield><subfield code="D">s</subfield></datafield><datafield tag="689" ind1="0" ind2="1"><subfield code="a">Meer</subfield><subfield code="0">(DE-588)4038301-5</subfield><subfield code="D">s</subfield></datafield><datafield tag="689" ind1="0" ind2="2"><subfield code="a">Hydroakustik</subfield><subfield code="0">(DE-588)4259255-0</subfield><subfield code="D">s</subfield></datafield><datafield tag="689" ind1="0" ind2=" "><subfield code="5">DE-604</subfield></datafield><datafield tag="856" ind1="4" ind2="2"><subfield code="m">Digitalisierung UB Bayreuth - ADAM Catalogue Enrichment</subfield><subfield code="q">application/pdf</subfield><subfield code="u">http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&local_base=BVB01&doc_number=029134433&sequence=000003&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA</subfield><subfield code="3">Inhaltsverzeichnis</subfield></datafield><datafield tag="856" ind1="4" ind2="2"><subfield code="m">Digitalisierung UB Bayreuth - ADAM Catalogue Enrichment</subfield><subfield code="q">application/pdf</subfield><subfield code="u">http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&local_base=BVB01&doc_number=029134433&sequence=000004&line_number=0002&func_code=DB_RECORDS&service_type=MEDIA</subfield><subfield code="3">Klappentext</subfield></datafield><datafield tag="999" ind1=" " ind2=" "><subfield code="a">oai:aleph.bib-bvb.de:BVB01-029134433</subfield></datafield></record></collection> |
id | DE-604.BV043722385 |
illustrated | Not Illustrated |
indexdate | 2024-07-10T07:33:24Z |
institution | BVB |
isbn | 9781107072343 |
language | English |
lccn | 016008185 |
oai_aleph_id | oai:aleph.bib-bvb.de:BVB01-029134433 |
oclc_num | 992495988 |
open_access_boolean | |
owner | DE-703 |
owner_facet | DE-703 |
physical | xxi, 420 pages |
publishDate | 2016 |
publishDateSearch | 2016 |
publishDateSort | 2016 |
publisher | Cambridge University Press |
record_format | marc |
spelling | Colosi, John A. Verfasser aut Sound propagation through the stochastic ocean John A. Colosi, Naval Postgraduate School New York, NY Cambridge University Press 2016 xxi, 420 pages txt rdacontent n rdamedia nc rdacarrier Includes bibliographical references and index Underwater acoustics Sound Transmission Oceanography Hydroakustik (DE-588)4259255-0 gnd rswk-swf Meer (DE-588)4038301-5 gnd rswk-swf Schallausbreitung (DE-588)4179359-6 gnd rswk-swf Schallausbreitung (DE-588)4179359-6 s Meer (DE-588)4038301-5 s Hydroakustik (DE-588)4259255-0 s DE-604 Digitalisierung UB Bayreuth - ADAM Catalogue Enrichment application/pdf http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&local_base=BVB01&doc_number=029134433&sequence=000003&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA Inhaltsverzeichnis Digitalisierung UB Bayreuth - ADAM Catalogue Enrichment application/pdf http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&local_base=BVB01&doc_number=029134433&sequence=000004&line_number=0002&func_code=DB_RECORDS&service_type=MEDIA Klappentext |
spellingShingle | Colosi, John A. Sound propagation through the stochastic ocean Underwater acoustics Sound Transmission Oceanography Hydroakustik (DE-588)4259255-0 gnd Meer (DE-588)4038301-5 gnd Schallausbreitung (DE-588)4179359-6 gnd |
subject_GND | (DE-588)4259255-0 (DE-588)4038301-5 (DE-588)4179359-6 |
title | Sound propagation through the stochastic ocean |
title_auth | Sound propagation through the stochastic ocean |
title_exact_search | Sound propagation through the stochastic ocean |
title_full | Sound propagation through the stochastic ocean John A. Colosi, Naval Postgraduate School |
title_fullStr | Sound propagation through the stochastic ocean John A. Colosi, Naval Postgraduate School |
title_full_unstemmed | Sound propagation through the stochastic ocean John A. Colosi, Naval Postgraduate School |
title_short | Sound propagation through the stochastic ocean |
title_sort | sound propagation through the stochastic ocean |
topic | Underwater acoustics Sound Transmission Oceanography Hydroakustik (DE-588)4259255-0 gnd Meer (DE-588)4038301-5 gnd Schallausbreitung (DE-588)4179359-6 gnd |
topic_facet | Underwater acoustics Sound Transmission Oceanography Hydroakustik Meer Schallausbreitung |
url | http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&local_base=BVB01&doc_number=029134433&sequence=000003&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&local_base=BVB01&doc_number=029134433&sequence=000004&line_number=0002&func_code=DB_RECORDS&service_type=MEDIA |
work_keys_str_mv | AT colosijohna soundpropagationthroughthestochasticocean |