Document 7189689
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Pacific Rim Underwater Acoustics Conference 2007
Ambient Noise Measurements
in East Sea
Youngshin Kim*, Hyoungsul La*, Jungyul Na*, Suntaek Oh**
*Dept. of Environmental Marine Sciences, Hanyang University,Korea
**STX Engine Company, Ltd.
[email protected]
Introduction of Experiment
2007 PRAUC
A pilot experiment of Acoustic Tomography
M-sequence
Peak Structure
Transmission Loss
Ocean Acoustics Laboratory of Hanyang University(OAL/HYU)
Applied Physics Laboratory of the University of Washington(APL/UW)
Pacific Oceanologic Institute(POI)
Hanyang University
Ocean Acoustics Laboratory
Objectives
2007 PRAUC
Characterize Ambient Noise
Depth dependence
Noise levels
Time variation
Figure out Noise source
Hanyang University
Ocean Acoustics Laboratory
Layout of Experiment
2007 PRAUC
Environment
VLA
Sea Surface Temp. (Satellite Picture )
Hanyang University
Ocean Acoustics Laboratory
Transmission schedule
Hanyang University
2007 PRAUC
Ocean Acoustics Laboratory
Receiver System
2007 PRAUC
Location : 37 32’34.6N, 13046’16.0E
VLA Depth : 290~380m
Hanyang University
Ocean Acoustics Laboratory
Recording System
2007 PRAUC
Recording time : about 47 hr (Oct.19~21,1999)
Recording period : every 2 hr for 80 min.
The Sample rate : 4 f0 Hz
HardWare Filter : Bandpass (200Hz ~ 700Hz)
Rotator
Recorder
TEAC
XR5000
수신기
Receiver
DEMUX
Demux
M6000
Multi-Ch
VLA Receiver
HP3562
Speaker
Configuration of the recording system
Hanyang University
HP3562A
DAT
Speaker
TEAC7000
Signal Analyzer
Monitor
Out
10-Ch
Oscilloscope
PC
TEK 434
Data
Translation
HP VEE
Program
Configuration of the A/D system
Ocean Acoustics Laboratory
Receiving Data
2007 PRAUC
Frequency (Hz)
366 Hz M-sequence
Power spectra density
(dB ref 1μPa2 / 1Hz)
Time (Sec)
Frequency (Hz)
Hanyang University
Ocean Acoustics Laboratory
Depth Dependence
2007 PRAUC
1/3 Octave band level
1/3 Octave band
No dependence
290~380m
Hanyang University
Depth(m)
VLA depth
Ocean Acoustics Laboratory
Noise Levels
2007 PRAUC
Spectrum Level
3 A.M.~7 A.M.
70 to 90 dB//1uPa//1Hz
Wenz Curve
3 ~ 7 A.M.
Other times
60 to 80 dB//1uPa//1Hz
Other times
Freq : 200~500Hz
Seastate : 4~5
Hanyang University
Ocean Acoustics Laboratory
Time Variations
2007 PRAUC
About 47 Hour
Frequency 200-500 Hz
Spectrum levels varied for 47 hours
500
Frequency (Hz)
400
Overload
300
200
13
15
17
19
20.OCT.
Hanyang University
23
1
3
5
7
9
11
13
15
21.OCT.
Recording Time (Hour)
17
19
21
23
1
3
5
7
9
22.OCT.
Ocean Acoustics Laboratory
11
Time Variations
2007 PRAUC
Power spectra density
(dB ref 1μPa2 / 1Hz)
Spectrum Level (1-Hz Band)
Frequency (Hz)
Power spectra density
(dB ref 1μPa2 / 1Hz)
Hardware filter effect
Hanyang University
Ocean Acoustics Laboratory
Spectrum level (Other Period)
2007 PRAUC
Frequency (Hz)
Time : 17 hour 20. OCT.– No tonal signals
Power spectra density
(dB ref 1μPa2 / 1Hz)
Time (Sec)
Frequency (Hz)
Hanyang University
Ocean Acoustics Laboratory
Spectrum level (dawn)
2007 PRAUC
Frequency (Hz)
Time : 3 A.M. – Tonal signals from ship
Power spectra density
(dB ref 1μPa2 / 1Hz)
Time (Sec)
Frequency (Hz)
Hanyang University
Ocean Acoustics Laboratory
Radiated Noise of Fishing Boat
2007 PRAUC
Measurement of Radiated Noise
Propulsions noise
Frequency (Hz)
Time (Sec)
Ref. KORDI
Hanyang University
Ocean Acoustics Laboratory
Squid Fishing ground site
2007 PRAUC
Fishing boat return to the port at dawn
VLA
Latitude
Х
Longitude
Ref. Status and forecasting for weekly Fishing Conditions (10.17~10~23),
National Fisheries Research Development Institute, KOREA, 1999
Hanyang University
Ocean Acoustics Laboratory
Vertical Beamforming
2007 PRAUC
Frequency : 300 hz
Distance ship noise
Time
Hanyang University
Ocean Acoustics Laboratory
Conclusion
2007 PRAUC
Measurement & analysis of the ambient noise in the East Sea
Frequency : 200-500 Hz
Ambient Noise Level at dawn(3-7 A.M.) are 5-10 dB higher than at
other time of day
Radiated Noise from the squid fishing boats
the main source of the high ambient noise level at dawn
Hanyang University
Ocean Acoustics Laboratory
Pacific Rim Underwater Acoustics Conference 2007
Thank You for your Attention