Fig. 2.1-1. MIMO-SAS using AUV 31

Fig. 2.1-2. Improved resolution of swath bathymetry using MIMO 32

Fig. 2.1-3. Increased array aperture using MIMO 32

Fig. 2.1-4. Structure of MIMO-FIM 32

Fig. 2.1-5. Performance of MIMO-FIM 32

Fig. 2.1-6. 3-D array structure for MIMO 33

Fig. 2.1-7. Performance of 3-D MIMO 33

Fig. 2.1-8. Side view of the experiments 34

Fig. 2.1-9. The end cap shape of the target 34

Fig. 2.1-10. The lake and the rail sonar system of experiments 35

Fig. 2.1-11. The cylinder target with inner plates 35

Fig. 2.3-1. Structure of the ceramic ring inside the Tonpilz vector sensor 37

Fig. 2.3-2. Tonpilz vector sensor 37

Fig. 2.3-3. Finite element model of the multimode spherical sensor 38

Fig. 2.3-4. Finite element model of the multimode ring sensor 38

Fig. 2.3-5. Photo of Hydroflown(Microflown Maritime) 39

Fig. 2.3-6. Photo of vector sensors from HZSonic(HZSonic) 39

Fig. 2.3-7. Conceptual drawing of an element of vector hydrophone(Benthowave Instrument Inc.) 40

Fig. 2.3-8. Drawing of towed array module. The towed array cable attaches to the far right 41

Fig. 2.3-9. Acoustic bearings of sperm whale clicks measured over a 5-h period... 41

Fig. 2.3-10. (a) Cardioid beam pattern (b) Map of relative locations of drilling site, DASARs, and whale signals 42

Fig. 2.3-11. Example of DASAR noise cancellation of industrial activity 42

Fig. 2.3-12. Developed acoustic system 43

Fig. 2.3-13. Examples of improved vector sensor array processing 43

Fig. 2.3-14. Source localization 44

Fig. 2.4-1. Noise hotspots in the ACCOBAMS area 45

Fig. 2.4-2. (a) signal due to propeller cavitation, (b) noise localization results 46

Fig. 2.4-3. Noise source localization experiments 46

Fig. 2.4-4. Noise mapping examples 47

Fig. 2.4-5. Marine ambient noise data visualization process 47

Fig. 2.4-6. Example of global-scale noise mapping 48

Fig. 2.5-1. The technology of horizontal array sensors 49

Fig. 2.5-2. The general configuration of horizontal array sensors 50

Fig. 2.5-3. The configuration of horizontal array sensor module 50

Fig. 3.1-1. High resolution beamforming based on Alternating projection... 52

Fig. 3.1-2. Ray-based blind deconvolution performance comparison between the conventional... 53

Fig. 3.1-3. Sonar imaging experiment for elastic target(aluminum cylindrical shell) using the clutter... 54

Fig. 3.1-4. Arrangement of water tank experiment of near field imaging 55

Fig. 3.1-5. Coordinate of near field 55

Fig. 3.1-6. Equation of near-field beamforming 55

Fig. 3.1-7. non of target 56

Fig. 3.1-8. Air-filled aluminum spherical shell 56

Fig. 3.1-9. Water-filled aluminum spherical shell 56

Fig. 3.1-10. The signal processing for SL calculation 57

Fig. 3.1-11. TVR of T335 58

Fig. 3.1-12. SL used T335 58

Fig. 3.1-13. The signal processing for TL calculation 58

Fig. 3.1-14. Raw data from TC 4032 58

Fig. 3.1-15. TL calculation 58

Fig. 3.1-16. The signal processing for calculation of signal level from KRISO array 59

Fig. 3.1-17. Channel average data 59

Fig. 3.1-18. Result of matched filter and beamforming processing 59

Fig. 3.1-19. SNR and processing gain table of KRISO array data 59

Fig. 3.1-20. Processing gain simulation 60

Fig. 3.1-21. Signal model for MIMO sonar 61

Fig. 3.1-22. Tx signal for MIMO 63

Fig. 3.1-23. Tx signal for phased array 63

Fig. 3.1-24. Tx signal for MIMO using m-sequence of length of 255 64

Fig. 3.1-25. Short Tx signal for MIMO 65

Fig. 3.1-26. PSL for m-seq and m-PSL seq 65

Fig. 3.1-27. MIMO Tx signal using OSW in the time-domain 66

Fig. 3.1-28. MIMO Tx signal using OSW in the frequency domain 66

Fig. 3.1-29. Output of matched filter for 10s 68

Fig. 3.1-30. Output of matched filter for the first frame of the low-band 68

Fig. 3.1-31. Output of matched filter for the first frame of the high-band 68

Fig. 3.1-32. MIMO-MUSIC Spectrum 69

Fig. 3.1-33. MIMO beam-pattern 69

Fig. 3.1-34. SIMO-MUSIC Spectrum 69

Fig. 3.1-35. SIMO beam-pattern 69

Fig. 3.1-36. MIMO-MUSIC Spectrum 69

Fig. 3.1-37. MIMO beam-pattern 69

Fig. 3.1-38. SIMO MUSIC Spectrum 70

Fig. 3.1-39. SIMO beam-pattern 70

Fig. 3.1-40. Output of matched filter of the low-band at the distance of 820 ms 70

Fig. 3.1-41. Output of matched filter of the high-band at the distance of＝820 ms 70

Fig. 3.1-42. MIMO-MUSIC spectrum 70

Fig. 3.1-43. MIMO beam-pattern 70

Fig. 3.1-44. SIMO-MUSIC spectrum 71

Fig. 3.1-45. SIMO beam-pattern 71

Fig. 3.1-46. Angular spectrum for MIMO, DOA＝0, 1 72

Fig. 3.1-47. Angular spectrum for MIMO, DOA＝0, 2 72

Fig. 3.1-48. Angular spectrum for MIMO, DOA＝0, 3 73

Fig. 3.1-49. Angular spectrum for MIMO, DOA＝0, 4 73

Fig. 3.1-50. Angular spectrum for MIMO, DOA＝0, 5 73

Fig. 3.1-51. Angular spectrum for MIMO, DOA＝0, 6 73

Fig. 3.1-52. Angular spectrum for MIMO, DOA＝0, 7 73

Fig. 3.1-53. Angular spectrum for MIMO, DOA＝0, 8 73

Fig. 3.1-54. Angular spectrum for MIMO, DOA＝0, 9 74

Fig. 3.1-55. Angular spectrum for MIMO, DOA＝0, 10 74

Fig. 3.1-56. Angular spectrum for SIMO, DOA＝0, 1 75

Fig. 3.1-57. Angular spectrum for SIMO, DOA＝0, 2 75

Fig. 3.1-58. Angular spectrum for SIMO, DOA＝0, 3 75

Fig. 3.1-59. Angular spectrum for SIMO, DOA＝0, 4 75

Fig. 3.1-60. Angular spectrum for SIMO, DOA＝0, 5 75

Fig. 3.1-61. Angular spectrum for SIMO, DOA＝0, 6 75

Fig. 3.1-62. Angular spectrum for SIMO, DOA＝0, 7 76

Fig. 3.1-63. Angular spectrum for SIMO, DOA＝0, 8 76

Fig. 3.1-64. Angular spectrum for SIMO, DOA＝0, 9 76

Fig. 3.1-65. Angular spectrum for SIMO, DOA＝0, 10 76

Fig. 3.1-66. Angular spectrum, DOA＝0, 3.6 77

Fig. 3.1-67. Angular spectrum, DOA＝0, 4.1 77

Fig. 3.1-68. Angular spectrum, DOA＝0, 8.3 77

Fig. 3.1-69. Angular spectrum, DOA＝0, 16.7 77

Fig. 3.1-70. Angular spectrum, DOA＝0, 41.3 77

Fig. 3.1-71. Correlation output 78

Fig. 3.1-72. Correlation output for the first frame 78

Fig. 3.1-73. Enlarged plot of the correlation output for the first frame 78

Fig. 3.1-74. Correlation output at 845 ms 78

Fig. 3.1-75. Normalized angular spectrum 78

Fig. 3.1-76. Un-normalized angular spectrum 78

Fig. 3.1-77. Tx signal for MIMO experiment using m-sequence 79

Fig. 3.1-78. Tx signal for MIMO experiment using m-PSL sequence 79

Fig. 3.1-79. Correlation output of Tx #1 80

Fig. 3.1-80. Enlarged plot of the correlation output of Tx #1 80

Fig. 3.1-81. Correlation output of Tx #3 80

Fig. 3.1-82. Enlarged plot of the correlation output of Tx #3 80

Fig. 3.1-83. Comparison of the angular spcetrum of MIMO/PA 80

Fig. 3.1-84. Correlation output of Tx #1 81

Fig. 3.1-85. Enlarged plot of the correlation output of Tx #1 81

Fig. 3.1-86. Correlation output of Tx #3 81

Fig. 3.1-87. Enlarged plot of the correlation output of Tx #3 81

Fig. 3.1-88. Comparison of the angular spcetrum of MIMO/PA 81

Fig. 3.1-89. Correlation output of Tx #1 82

Fig. 3.1-90. Enlarged plot of the correlation output of Tx #1 82

Fig. 3.1-91. Correlation output of Tx #3 82

Fig. 3.1-92. Enlarged plot of the correlation output of Tx #3 82

Fig. 3.1-93. Comparison of the angular spcetrum of MIMO/PA 82

Fig. 3.1-94. Correlation output of Tx #1 83

Fig. 3.1-95. Enlarged plot of the correlation output of Tx #1 83

Fig. 3.1-96. Correlation output of Tx #3 83

Fig. 3.1-97. Enlarged plot of the correlation output of Tx #3 83

Fig. 3.1-98. Comparison of the angular spcetrum of MIMO/PA 83

Fig. 3.1-99. The comparison of frequency response of spherical... 84

Fig. 3.1-100. The comparison of scattering signal of time-domain of... 84

Fig. 3.1-101. The arrangements of water tank experiments 85

Fig. 3.1-102. The picture of the water tank experiments 85

Fig. 3.1-103. The aluminum spherical shell target 86

Fig. 3.1-104. Time-domain signal of no target case 86

Fig. 3.1-105. Time-domain signal of air-filled case 86

Fig. 3.1-106. Time-domain signal of water-filled case 86

Fig. 3.1-107. Target strength of air-filled aluminum spherical shell of the first water tank experiments 87

Fig. 3.1-108. Target strength of air-filled aluminum spherical shell of the second water tank experiments 87

Fig. 3.1-109. Target strength of water-filled aluminum spherical shell of the first water tank experiments 87

Fig. 3.1-110. Target strength of water-filled aluminum spherical shell of the second water tank experiments 87

Fig. 3.1-111. Target echoes by air-filled aluminum spherical shell 88

Fig. 3.1-112. Target echoes by air-filled plastic spherical shell 88

Fig. 3.1-113. PWVD of air-filled aluminum spherical shell 89

Fig. 3.1-114. PWVD of water-filled aluminum spherical shell 89

Fig. 3.1-115. Average of frequency of guided wave 90

Fig. 3.1-116. Energy of frequency of guided wave 90

Fig. 3.1-117. Standard deviation of frequency of guided wave 90

Fig. 3.1-118. The arrangement of bistatic scattering experiments of aluminum spherical shell in the water tank 90

Fig. 3.1-119. The scattering of aluminum spherical shell from Ch.1 hydrophone 91

Fig. 3.1-120. The scattering of aluminum spherical shell from Ch.2 hydrophone 91

Fig. 3.2-1. Schematic and coordinate system of sea experiments conducted near Jinhae Port 93

Fig. 3.2-2. (a) Sound speed profile (b) Horizontal array sensor layout 93

Fig. 3.2-3. Shock signal received through horizontal array sensor(position # 20) 94

Fig. 3.2-4. Beamforming result using signal of Fig. 3.2-3(position # 20) 94

Fig. 3.2-5. The sound source distance estimation using impulse sound signal(position # 20). 94

Fig. 3.2-6. Schematic of sea experiments(Jangmok Port experiments, May 2019) 95

Fig. 3.2-7. (a) The sea experiment schematic, (b) The sound speed profile, (c) The... 96

Fig. 3.2-8. (a) Time series signal and (b) Spectrogram of received signal 96

Fig. 3.2-9. The result of beamforming using Fig. 3.2-8 (a) 97

Fig. 3.2-10. (a) Channel impulse response estimated using matched filter, (b) Beam-time domain and... 97

Fig. 3.2-11. (a) The schematic of SAVEX15 experiments, (b) GPS data:... 98

Fig. 3.2-12. (a) CIR estimation from ship noise using RBD, (b) beam-time domain 99

Fig. 3.2-13. (a) Tracking results of the ship using the proposed AI, (b) Distance... 99

Fig. 3.2-14. (a) The schematic and (b) the path of the ship of SAVE＝15 experiments 100

Fig. 3.2-15. (a) typical beamforming results, (b) channel impulse response, and... 101

Fig. 3.2-16. (a) The objective function results according to the inclination of the array... 101

Fig. 3.2-17. (a) typical beamforming results, (b) channel impulse response, and (c)... 102

Fig. 3.2-18. (a) The objective function results according to the inclination of the array... 103

Fig. 3.2-19. Ship tracking results for a total of 4 hours; (a) Distance estimation result,... 103

Fig. 3.2-20. The estimated slope of the array for a total of 4 hours 104

Fig. 3.2-21. The schematic diagram of the back propagation path of sound ray... 105

Fig. 3.2-22. (a) beamforming output of the ship noise and (b) back propagation... 106

Fig. 3.2-23. (a) The objective function , (b) The sound arrival time... 106

Fig. 3.2-24. The result of back propagation of the sound ray after... 106

Fig. 3.2-25. (a) The beamforming of the ship noise and (b) back propagation results... 107

Fig. 3.2-26. (a) The objective function , (b) The sound arrival time difference 107

Fig. 3.2-27. The result of back propagation of the sound ray after... 107

Fig. 3.3-1. Circular array configuration for beamforming simulation 110

Fig. 3.3-2. Beamforming performance for various parameters and algorithms 112

Fig. 3.3-3. Beamforming performance index #1 for various parameters 113

Fig. 3.3-4. Beamforming performance index #2 for various parameters 114

Fig. 3.3-5. Beamforming performance index #3 for various parameters 114

Fig. 3.3-6. Estimation of amplitude and phase using curve fitting 115

Fig. 3.3-7. Estimated particle velocity 115

Fig. 3.3-8. Comparison of beamforming power using various sensor data 116

Fig. 3.3-9. Acoustic scattering by cylindrical structure 117

Fig. 3.3-10. Acoustic scattering by cylindrical structure 118

Fig. 3.3-11. Pressure along the cylindrical surface for various r/λ 119

Fig. 3.3-12. Comparison of sound fields with and without scattering 120

Fig. 3.3-13. Beamforming simulation results using cylindrical sensor 121

Fig. 3.3-14. Manufactured cylindrical sensor for verification of beamfomring algorithms 122

Fig. 3.3-15. Block diagram and frequency response of the preamplifier 123

Fig. 3.3-16. Receiving sensitivity of the transducer units 123

Fig. 3.3-17. Receiving sensitivity of the transducer units 124

Fig. 3.3-18. Experimental set-up for the tank test 124

Fig. 3.3-19. Equipment set-up for the tank test 125

Fig. 3.3-20. Snap shots of the tank test 125

Fig. 3.3-21. Beamforming results of the tank test(6kHz Tone) 126

Fig. 3.3-22. Beamforming results of the tank test(5~7kHz MLS) 126

Fig. 3.3-23. Experimental set-up for the lake test 127

Fig. 3.3-24. Equipment set-up for the lake test 127

Fig. 3.3-25. Snap shots of the lake test 128

Fig. 3.3-26. Beamforming results of the lake test(6kHz Tone) 128

Fig. 3.3-27. Beamforming results of the lake test(5~7kHz MLS) 129

Fig. 3.4-1. History of propeller cavitation noise numerical prediction... 131

Fig. 3.4-2. Comparison of ship noise prediction results with measured data 132

Fig. 3.4-3. AIS stations registered in AIS Hub 133

Fig. 3.4-4. Examples of ship traffic status (left) and traffic density during... 133

Fig. 3.4-5. An example of ship information obtained from AIS 134

Fig. 3.4-6. Shipping noise mapping example 134

Fig. 3.4-7. AIS data for noise mapping simulation 135

Fig. 3.4-8. Shipping noise simulation results using AIS data 135

Fig. 3.4-9. Schematic diagram of noise mapping simulation program 139

Fig. 3.4-10. Bathymetry for simulation 140

Fig. 3.4-11. 3D transmission loss calculation for target ship #1 140

Fig. 3.4-12. Noise map calculated at a typical time 141

Fig. 3.4-13. Statistical analysis of 2 hour shipping noise 141

Fig. 3.4-14. Spectrogram of measured data 144

Fig. 3.4-15. Noise mapping process 144

Fig. 3.4-16. Bottom properties estimated using geoacoustic inversion 145

Fig. 3.4-17. Example of estimated source levels 145

Fig. 3.4-18. Comparison of bearing estimation (left) and DGPS position on noise map (right) 145

Fig. 3.5-1. Conceptual image of KRISO mid-frequency acoustic array... 146

Fig. 3.5-2. Components of KRISO mid-frequency acoustic array system 147

Fig. 3.5-3. Block diagram of receiver part(휴엔스, 2017) 149

Fig. 3.5-4. Block diagram of preconditioning amp(전치증폭기)(휴엔스, 2017) 149

Fig. 3.5-5. Block diagram of RX amp and conditioning filters(수신 증폭기 및 필터)(휴엔스, 2017) 149

Fig. 3.5-6. Hydrophone sensitivity verification(Huens) 150

Fig. 3.5-7. Hydrophone sensitivity measured in UTEC water basin by KRISO 151

Fig. 3.5-8. Block diagram of receiver part(휴엔스, 2017) 151

Fig. 3.5-9. Block diagram of power amplifier(휴엔스, 2018) 151

Fig. 3.5-10. Sensitivity and representative beam pattern of Neptune T335 152

Fig. 3.5-11. Dimension of prototype model 153

Fig. 3.5-12. Part plan of prototype model 153

Fig. 3.5-13. Modeling appearance of prototype model 154

Fig. 3.5-14. Center of gravity 154

Fig. 3.5-15. Manufactured prototype model 154

Fig. 3.5-16. Linear water tank test 156

Fig. 3.5-17. AHRS used to measure posture 156

Fig. 3.5-18. Measurement result in horizontal state outside the tank 157

Fig. 3.5-19. Measurement result after ballast in water tank 157

Fig. 3.5-20. Modeling appearance of 1st model 157

Fig. 3.5-21. Dimension of 1st model 158

Fig. 3.5-22. Manufactured 1st model 158

Fig. 3.5-23. Water tank test of 1st model 159

Fig. 3.5-24. Forces on 1st model 159

Fig. 3.5-25. Change of strut cross section 162

Fig. 3.5-26. Pitch angle variation of the array sensor platform by uniform flow velocity increment 162

Fig. 3.5-27. Circulating water tank test of 1st model 163

Fig. 3.5-28. Circulating water tank test of 1st model 163

Fig. 3.5-29. The recorded pitch angle along the each circulation velocities 164

Fig. 3.5-30. Buoyancy control unit operational concept 165

Fig. 3.5-31. System configuration of array sensor 165

Fig. 3.5-32. Concept diagram 166

Fig. 3.5-33. Dimension of 1st posture control unit 166

Fig. 3.5-34. Manufactured 1st posture control unit 166

Fig. 3.5-35. Mounted 1st posture control unit 167

Fig. 3.5-36. Control flowchart of posture control unit 167

Fig. 3.5-37. Control program 168

Fig. 3.5-38. Array platform sensor information display 168

Fig. 3.5-39. Log saving and operation setting part 168

Fig. 3.5-40. Control parameter setting part 169

Fig. 3.5-41. Posture control information display 169

Fig. 3.5-42. Posture control unit setting part 170

Fig. 3.5-43. Operation log display 170

Fig. 3.5-44. Dimension of 2nd model 171

Fig. 3.5-45. Newly manufactured outer frame 171

Fig. 3.5-46. Outer frame composition 172

Fig. 3.5-47. Outer frame type 172

Fig. 3.5-48. Buoyancy material shape 172

Fig. 3.5-49. Bow/stern cone shape 173

Fig. 3.5-50. Strut composition 174

Fig. 3.5-51. Drag reduction pin shape 174

Fig. 3.5-52. Manufactured 2nd model 175

Fig. 3.5-53. Pitch angle change graph 176

Fig. 3.5-54. Pitch angle change by current velocity 177

Fig. 3.5-55. Depth change by pitch angle 177

Fig. 3.5-56. Matching point of drag force and buoyancy 178

Fig. 3.5-57. Circulating water tank test configuration 188

Fig. 3.5-58. Circulating water tank test scene 189

Fig. 3.5-59. Operation test of posture control unit 192

Fig. 3.5-60. Dimension of 2nd posture control unit 195

Fig. 3.5-61. Mounted 2nd posture control unit 195

Fig. 3.5-62. Lifting load test on air 197

Fig. 3.5-63. Control command and actual position 197

Fig. 3.5-64. Pressure test of urethane coated buoyancy materials 198

Fig. 3.5-65. Pressure test 199

Fig. 3.5-66. Buoyant weight change 199

Fig. 3.5-67. Manufacture of commercial buoyancy materials 200

Fig. 3.5-68. Same directional drive of bow and stern posture control unit 201

Fig. 3.5-69. Reverse directional drive of bow and stern posture control unit 201

Fig. 3.5-70. Array platform mounted on the structure 202

Fig. 3.5-71. Operation test of posture control unit 202

Fig. 3.5-72. Experimental set-up for measuring acoustic characteristics of the array platform(top view) 203

Fig. 3.5-73. Experimental set-up for measuring acoustic characteristics of the array platform(front view) 203

Fig. 3.5-74. Equipment set-up for measuring acoustic characteristics of the array platform 204

Fig. 3.5-75. Measured background noise level using B&K Type＝8103 hydrophones 205

Fig. 3.5-76. Measured background noise level using the array platform 206

Fig. 3.5-77. Frequency and impulse responses without the array platform 206

Fig. 3.5-78. Frequency and impulse responses with the array platform 207

Fig. 3.5-79. Comparison of impulse responses with and without the array platform 207

Fig. 3.5-80. Comparison of frequency responses with and without the array platform 208

Fig. 3.5-81. Comparison of the estimated TVR with the result measured in the anechoic tank in KRISO 208

Fig. 3.5-82. Measured RVSs of the hydrophones in the array platform 209

Fig. 3.5-83. Measured RVSs of the hydrophones in the array platform 209