Underwater Sound Propagation and Acoustic Communication in A Time-varying Shallow Estuarine ...

152 Pages·2017·2.81 MB·English

by  Zheguang Zou

UNDERWATER SOUND PROPAGATION AND
ACOUSTIC COMMUNICATION IN
A TIME-VARYING SHALLOW ESTUARINE ENVIRONMENT
by
Zheguang Zou
A dissertation submitted to the Faculty of the University of Delaware in partial
fulfillment of the requirements for the degree of Doctor of Philosophy in Oceanography
Fall 2017
(cid:13)c 2017 Zheguang Zou
All Rights Reserved
UNDERWATER SOUND PROPAGATION AND
ACOUSTIC COMMUNICATION IN
A TIME-VARYING SHALLOW ESTUARINE ENVIRONMENT
by
Zheguang Zou
Approved:
Mark A. Moline, Ph.D.
Director of the School of Marine Science and Policy
Approved:
Estella Atekwana, Ph.D.
Dean of the College of Earth, Ocean, and Environment
Approved:
Ann L. Ardis, Ph.D.
Senior Vice Provost for Graduate and Professional Education
I certify that I have read this dissertation and that in my opinion it meets the
academicandprofessionalstandardrequiredbytheUniversityasadissertation
for the degree of Doctor of Philosophy.
Signed:
Mohsen Badiey, Ph.D.
Professor in charge of dissertation
I certify that I have read this dissertation and that in my opinion it meets the
academicandprofessionalstandardrequiredbytheUniversityasadissertation
for the degree of Doctor of Philosophy.
Signed:
Xiaomei Xu, Ph.D.
Member of dissertation committee
I certify that I have read this dissertation and that in my opinion it meets the
academicandprofessionalstandardrequiredbytheUniversityasadissertation
for the degree of Doctor of Philosophy.
Signed:
Lin Wan, Ph.D.
Member of dissertation committee
I certify that I have read this dissertation and that in my opinion it meets the
academicandprofessionalstandardrequiredbytheUniversityasadissertation
for the degree of Doctor of Philosophy.
Signed:
Fabrice Veron, Ph.D.
Member of dissertation committee
I certify that I have read this dissertation and that in my opinion it meets the
academicandprofessionalstandardrequiredbytheUniversityasadissertation
for the degree of Doctor of Philosophy.
Signed:
I. Pablo Huq, Ph.D.
Member of dissertation committee
ACKNOWLEDGEMENTS
I would like to thank my advisor, Dr. Mohsen Badiey, for his help and guidance
throughout my PhD journey. He is so passionate and creative, and is always there
to help me to challenge the unknown. I would also like to thank my co-advisor, Dr.
Xiaomei Xu, for all her supports. Without her, I will not be able to come this far.
Meanwhile, I thank all my committee members, Dr. Lin Wan, Dr. Fabrice Veron, and
Dr. Pablo Huq, for their great suggestions to make this dissertation better. I also
thank my colleagues in the Ocean Acoustics Labs, Dr. Aijun Song, Dr. Entin Karjadi,
and Dr. Justin Eickmeier, for their help with this study.
In addition, a big thank you to fellow students in Robinson Hall and all my
good friends in Newark. My life in the America was so colorful because of you. I also
would like to thank my parents, family, and friends back in China. Your unconditional
love and support help me fly under the most colorful and unlimited sky.
v
TABLE OF CONTENTS
LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x
LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
Chapter
1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 DIRECT-PATH SOUND FADING IN A SHALLOW
TIDAL-STRAINING ESTUARY . . . . . . . . . . . . . . . . . . . . 8
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2 The Direct-Path Fading Phenomenon . . . . . . . . . . . . . . . . . . 11
2.2.1 Description of the HFA97 experiment . . . . . . . . . . . . . . 11
2.2.2 The observed phenomenon . . . . . . . . . . . . . . . . . . . . 13
2.3 Field Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.3.1 Environmental data . . . . . . . . . . . . . . . . . . . . . . . . 16
2.3.2 Acoustical data . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3.3 Correlations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.4 The Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2.4.1 Physical oceanography . . . . . . . . . . . . . . . . . . . . . . 24
2.4.2 Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.5 Acoustic Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2.5.1 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.5.2 Modeling the effect of sound speed gradient . . . . . . . . . . 31
vi
2.5.3 Modeling the direct path fading in the HFA97 experiment . . 35
2.6 Discussions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.6.1 Physical oceanography . . . . . . . . . . . . . . . . . . . . . . 38
2.6.2 Acoustics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
2.7 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3 EFFECTS OF WIND SPEED ON SHALLOW-WATER
BROADBAND ACOUSTIC TRANSMISSION . . . . . . . . . . . . 45
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
3.2 Field Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
3.2.1 Description of the Experiment . . . . . . . . . . . . . . . . . . 47
3.2.1.1 Acoustic channel . . . . . . . . . . . . . . . . . . . . 48
3.2.1.2 Surface measurements . . . . . . . . . . . . . . . . . 49
3.2.1.3 Oceanographic measurements . . . . . . . . . . . . . 50
3.2.2 Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.2.2.1 Two wind cases . . . . . . . . . . . . . . . . . . . . . 51
3.2.2.2 Surface roughness and Rayleigh parameter . . . . . . 53
3.2.2.3 Wind speed correlation . . . . . . . . . . . . . . . . . 54
3.3 Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
3.3.1 Modeling Methods . . . . . . . . . . . . . . . . . . . . . . . . 56
3.3.1.1 Shallow-water waves . . . . . . . . . . . . . . . . . . 57
3.3.1.2 Acoustic modeling . . . . . . . . . . . . . . . . . . . 58
3.3.2 Modeling Analysis . . . . . . . . . . . . . . . . . . . . . . . . 59
3.3.2.1 Two wind cases . . . . . . . . . . . . . . . . . . . . . 59
3.3.2.2 Roughness and Rayleigh parameter . . . . . . . . . . 60
3.3.2.3 Wind correlation . . . . . . . . . . . . . . . . . . . . 62
3.4 Model Prediction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
3.5 Data-Model Comparison . . . . . . . . . . . . . . . . . . . . . . . . . 67
3.6 Discussions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
vii
3.7 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
4 MODELING ACOUSTIC COHERENT COMMUNICATION
UNDER WIND-DRIVEN OCEAN SURFACE WAVES . . . . . . 73
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
4.2 Modeling Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
4.2.1 Wind-impacted time-evolving acoustic channel . . . . . . . . . 76
4.2.2 QPSK acoustic communication system . . . . . . . . . . . . . 79
4.3 Modeling Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
4.3.1 Environmental and channel variability . . . . . . . . . . . . . 82
4.3.2 Acoustic communication performance . . . . . . . . . . . . . . 84
4.4 Discussions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
4.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
5 WIND-WAVE EFFECTS ON COHERENT AND
NON-COHERENT UNDERWATER ACOUSTIC
COMMUNICATIONS: A LABORATORY EXPERIMENT . . . . 88
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
5.2 The Water Tank Experiment . . . . . . . . . . . . . . . . . . . . . . . 92
5.2.1 The environment and experimental setup . . . . . . . . . . . . 93
5.2.2 Tested acoustic communication schemes . . . . . . . . . . . . 95
5.3 Analysis of Underwater Acoustic Channels . . . . . . . . . . . . . . . 97
5.3.1 Acoustic channel impulse response . . . . . . . . . . . . . . . 97
5.3.2 Channel variability . . . . . . . . . . . . . . . . . . . . . . . . 100
5.3.3 Temporal coherence . . . . . . . . . . . . . . . . . . . . . . . . 103
5.4 Performance Analysis of Acoustic Communication . . . . . . . . . . . 104
5.4.1 Coherent communication . . . . . . . . . . . . . . . . . . . . . 104
5.4.2 Non-coherent communication . . . . . . . . . . . . . . . . . . 108
5.5 Discussions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
5.6 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
viii
6 CONCLUSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Appendix
A COPYRIGHT PERMISSION . . . . . . . . . . . . . . . . . . . . . . . 130
ix
LIST OF TABLES
2.1 Statistical values for the water properties during the HFA97
experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2 Correlation coefficients of sound speed gradient at different depths
with tide (R ) and current velocity (R ). . . . . . . . . . . . . . 23
h,c u,c
3.1 Correlation Coefficients between Surface Wind Speed and
Surface-Group Pressure Amplitude . . . . . . . . . . . . . . . . . . 56
5.1 List of all wind/surface scenarios and their associated signal temporal
coherence from the tank experiment. . . . . . . . . . . . . . . . . . 103
x