Present measurement and characterization of ambient noise that has been conducted in coastal environments of Surabaya.

1. Ambient Noise Measurement and Characterization
of Underwater Acoustic Channel in Surabaya Bay
Tri Budi Santoso, Endang Widjiati, Wirawan, Gamantyo Hendrantoro
Electrical Department, Institut Teknologi Sepuluh Nopember
IEEE Asia Pacific Conference on Wireless and Mobile
Bandung-Indonesia, August 27-29, 2015

2. Outline Presentation
• Introduction
• Environment and Experimental Set-Up
• Data Analysis
• Conclusion

3. Ambient noise[1][2]:
•Generally appears continually at a certain location.
•Determines the baseline sound scape
I. INTRODUCTION
Current Research:
•The effects of wind and ship movement on acoustic noise [5] – [11]
•Time-frequency analysis of ambient noise measurement [12]
•Effect of seabed conditions in shallow waters on ambient noise [13]
[14]

4. This paper:
•Present measurement and characterization of ambient
noise that has been conducted in coastal environments
of Surabaya.
•Represent a condition of tropical shallow water
environment.
INTRODUCTION

5. • Description of Environmental Measurement
• Hydrophone Normalization
• Experimental Set-Up
II. ENVIRONMENT AND EXPERIMENTAL SET-UP

6. A. Description of Environmental Measurement
Coordinates: (7°0′~7°30′(S); 112°30′~113°0′(E))
Relative busy traffic, 200 m from beach, 2.4 m depth
Environment temperature: 32.7o
C, noise: 46.8 ~ 53 dB
ENVIRONMENT AND EXPERIMENTAL SET-U

7. B. Hydrophone Normalization
Testing Signal: LFM 1~15 kHz
Receiver: 3 hydrophones
ADC: Digital Mixer (M-Audio)
Ratio between hydrophones:
H-123 : H-2 = 1.9,
H-ref : H-2 = 0.65,
H-123 : H-ref = 1.7.
ENVIRONMENT AND EXPERIMENTAL SET-U

8. C. Experimental Set-Up
Recording: 2 locations x three times,
duration of 20 second
Totally obtain 18 data measurements
ENVIRONMENT AND EXPERIMENTAL SET-U

9. III. DATA ANALYSIS
Time Domain Analysis Frequency Domain Analysis

10. A. Time Domain Analysis of Ambient Noise
DATA ANALYSIS
Noise level fluctuations, around the zero level,
Any part has a value of about -0.01 V or 0.01 V

11. DATA ANALYSIS
Statistical Analysis:
Mean: -2.85 x 10-5
V,
Standard deviation of 9.87 x 10-4
V
Fitting with Gaussian distribution:
(mean=0, standard deviation, σ = 9.87 x 10-4
)
-MSE : 9.96 x10-5
-Bhattacharya distance : 3.54 x 10-4

12. B. Frequency Domain Analysis of Ambient Noise
DATA ANALYSIS
Frequency range:
0 ~ 9 kHz: decreasing - 90 dB ~ - 140 dB
negative logarithmic function : y = ln xa
+ b.
a = -11.5, b = -30.
Frequency range:
9 ~ 13.5 kHz,
noise power level is quite flat
Frequency range:
14 kHz ~ 18 kHz,
noise power level has a
fluctuation

13. IV.
CONCLUSION
Ambient noise characterization:
•Pdf is close to Gaussian distribution with zero mean, standard
deviation of 9.87 x 10-4
V.
•Frequency range (9 kHz ~ 13.5 kHz), shows a flat spectrum,
represents an AWGN channel conditions.
•The modeling of UWA communication system can be done by
adopting the model of digital communication systems in AWGN
channel, in the frequency range.