scholarly journals Experimental Study on Source Level Estimation Techniques of Underwater Sound Source in Reverberant Water Tank

2019 ◽  
Vol 33 (4) ◽  
pp. 358-363 ◽  
Author(s):  
Kookhyun Kim
Keyword(s):  
Experimental Study ◽  
Sound Source ◽  
Water Tank ◽  
Underwater Sound ◽  
Estimation Techniques ◽  
Source Level

Relationship of swim-bladder shape to the directionality pattern of underwater sound in the oyster toadfish

1998 ◽  
Vol 76 (1) ◽  
pp. 134-143 ◽  
Author(s):  
John F Barimo ◽  
Michael L Fine
Keyword(s):  
Sound Source ◽  
Sound Pressure ◽  
Sound Production ◽  
Swim Bladder ◽  
Underwater Sound ◽  
York River ◽  
Coefficients Of Variation ◽  
Source Level ◽  
Oyster Toadfish ◽  
Relationship Of

The swim bladder of the oyster toadfish, Opsanus tau, has a distinctive heart shape with two anterior protrusions separated by a midline cleft. The lateral surfaces contain intrinsic muscles that meet at the caudal midline, but the rostromedial surface is muscle-free. We hypothesize that swim-bladder design represents a compromise between opposing tendencies toward (i) an omnidirectional sound source that would optimize a male's opportunity to attract females from any direction, and (ii) a directional sound source that would shield the nearby ears during sound production. To determine if the directionality of toadfish sound is consistent with this hypothesis, boatwhistle advertisement calls of individually identified males were recorded in the York River, Virginia, by means of two calibrated hydrophones and a waterproof recording system: one hydrophone was fixed 1 m in front of the fish and the second was roving. Boatwhistles in the horizontal plane propagated in a modified omnidirectional pattern that was bilaterally symmetrical. The mean sound pressure was 126 dB re: 1 µPa at 0°. The sound pressure level decreased by approximately 1 dB at ±45°, after which levels increased to 180°, averaging 3-6 dB greater behind (mean 130 dB) than directly in front of the fish. This pattern is consistent with the hypothesis that sound energy is reduced at the fish's ears. The source level and fundamental frequency of the boatwhistle were highly stereotyped, with coefficients of variation averaging less than 1%, and duration was more variable, with a coefficient of variation of 8%. Grunt levels overlapped but were slightly lower than boatwhistle values.

scholarly journals A Reference Spectrum Model for Estimating Source Levels of Marine Shipping Based on Automated Identification System Data

2021 ◽  
Vol 9 (4) ◽  
pp. 369 ◽  
Author(s):  
Alexander MacGillivray ◽  
Christ de Jong
Keyword(s):  
Objective Assessment ◽  
Noise Pollution ◽  
Specific Reference ◽  
Identification System ◽  
Reference Spectrum ◽  
Underwater Sound ◽  
The North ◽  
Joint Monitoring ◽  
Source Level ◽  
Spectrum Model

Underwater sound mapping is increasingly being used as a tool for monitoring and managing noise pollution from shipping in the marine environment. Sound maps typically rely on tracking data from the Automated Information System (AIS), but information available from AIS is limited and not easily related to vessel noise emissions. Thus, robust sound mapping tools not only require accurate models for estimating source levels for large numbers of marine vessels, but also an objective assessment of their uncertainties. As part of the Joint Monitoring Programme for Ambient Noise in the North Sea (JOMOPANS) project, a widely used reference spectrum model (RANDI 3.1) was validated against statistics of monopole ship source level measurements from the Vancouver Fraser Port Authority-led Enhancing Cetacean Habitat and Observation (ECHO) Program. These validation comparisons resulted in a new reference spectrum model (the JOMOPANS-ECHO source level model) that retains the power-law dependence on speed and length but incorporates class-specific reference speeds and new spectrum coefficients. The new reference spectrum model calculates the ship source level spectrum, in decidecade bands, as a function of frequency, speed, length, and AIS ship type. The statistical uncertainty (standard deviation of the deviation between model and measurement) in the predicted source level spectra of the new model is estimated to be 6 dB.

scholarly journals ENGINEERING OF ACOUSTIC TECHNOLOGY FOR UNDERWATER POSITIONING OBJECT

2018 ◽  
Vol 10 (3) ◽  
pp. 629-637
Author(s):  
Billi Rifa Kusumah ◽  
Indra Jaya ◽  
Henry M. Manik ◽  
. Susilohadi
Keyword(s):  
Control System ◽  
Sound Source ◽  
Arrival Time ◽  
Equation Model ◽  
Control Device ◽  
Electromagnetic Signal ◽  
Positioning System ◽  
Underwater Sound ◽  
Underwater Positioning ◽  
The Difference

Underwater Positioning System (UPS) is a system to track the existence of the position of an object by utilizing the arrival time of the signal measurement. On land, the system uses an electromagnetic signal called GPS. However, because it cannot penetrate water effectively, an acoustic signal is used as an alternative. The purpose of this research is to engineer the control system of data acquisition and underwater acoustic device to measure arrival time (TOA) and apply equation model for underwater sound source positioning system. the effective frequency resonance of the transducer and the hydrophone is at a frequency of 6 kHz. The acquisition control device is able to measure the TOA signal with an error on a digital channel smaller than an analog channel. The difference between the TOA values measured by oscilloscope and acquisition control system is caused by inaccuracy of threshold estimates at the receiver's peak detector circuit. The position of the sound source coordinates obtained from the equation model shows the highest difference in depth point (z) compared to points (x) and (y), caused by the equation model used is limited to four hydrophone units forming a horizontal baseline.

Modeling and electromechanical performance analysis of frequency-variable piezoelectric stack transducers

2020 ◽  
Vol 31 (6) ◽  
pp. 897-910
Author(s):  
Jianjun Wang ◽  
Shuyuan Cai ◽  
Lei Qin ◽  
Donghuan Liu ◽  
Peijun Wei ◽  
...  
Keyword(s):  
Experimental Study ◽  
Performance Analysis ◽  
Analytical Solution ◽  
Resonance Frequency ◽  
Analytical Model ◽  
Dynamic Characteristics ◽  
Active Element ◽  
Underwater Sound ◽  
Layer Number ◽  
Electromechanical Performance

An exact analytical model of frequency-variable piezoelectric stack transducers is proposed, and their dynamic characteristics are studied in this article. Based on the linear piezoelasticity theory, the dynamic analytical solution is first derived, and then its correctness is validated by comparing it with the results of a special example in the previous literature and the ones of the experimental study. The effects of the tuning resistance and the layer number of the active element on the dynamic characteristics are discussed. Numerical results show that tuning the resistance and the layer number of the active element can enable the multi-frequency characteristics of the piezoelectric stack transducers. A proper layer number of the active element can minimize the short-circuited resonance frequency and the open-circuited anti-resonance frequency. These findings provide guidelines to design and optimize the piezoelectric stack transducers, which have promising potential in developing the multi-frequency Langevin transducers for some underwater sound and ultrasonic applications, such as ultrasonic cleaning, ultrasonic chemistry, and sonar radiators.

Standards for measurement and reporting of underwater sound: Application to the source level of trailing suction hopper dredgers.

2011 ◽  
Vol 129 (4) ◽  
pp. 2461-2461
Author(s):  
Christ A. F. de Jong ◽  
Michael A. Ainslie ◽  
Erwin W. Jansen ◽  
Benoit A. J. Quesson
Keyword(s):  
Underwater Sound ◽  
Source Level

scholarly journals Experimental Study on Dynamic Heat Release Performance of Water Tank with Phase Change Materials

2019 ◽  
Vol 158 ◽  
pp. 5006-5013 ◽  
Author(s):  
Jin Li ◽  
Enshen Long ◽  
Fei Liang ◽  
Hang Zou ◽  
Ning Mao
Keyword(s):  
Experimental Study ◽  
Phase Change ◽  
Heat Release ◽  
Phase Change Materials ◽  
Water Tank

Monopole-driven underwater sound source

2005 ◽  
Vol 117 (4) ◽  
pp. 1688
Author(s):  
Hans Thomas Rossby ◽  
James H. Miller
Keyword(s):  
Sound Source ◽  
Underwater Sound

Sound Silencing Problem of Underwater Vehicles

2013 ◽  
Vol 196 ◽  
pp. 212-219 ◽  
Author(s):  
Karol Listewnik
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Water Environment ◽  
Underwater Vehicle ◽  
Underwater Vehicles ◽  
Negative Influence ◽  
Water Tank ◽  
Underwater Sound ◽  
Military Applications ◽  
Paper Review ◽  
Common Problems

This paper describes some common problems associated with negative influence of UUV self noise on detection aspect in water environment. Some tasks of military applications require silent behavior of UUVs: Intelligence, Surveillance, and Reconnaissance (ISR), Rapid Environmental Assessment (REA), Mine Countermeasure (MCM) etc. Moreover, this paper review methods of underwater sound measurement and on the end as a summary presents results of an experiment from the water tank trials where were investigated three UUVs: one ROV and two biomimetic autonomous underwater vehicle.

A Passive Acoustic Positioning Algorithm Based on Virtual Long Baseline Matrix Window

2018 ◽  
Vol 72 (1) ◽  
pp. 193-206 ◽  
Author(s):  
Tao Zhang ◽  
Ziqiang Wang ◽  
Yao Li ◽  
Jinwu Tong
Keyword(s):  
Sound Source ◽  
Cross Correlation ◽  
Autonomous Underwater Vehicles ◽  
Underwater Sound ◽  
Positioning Systems ◽  
Long Baseline ◽  
Positioning Method ◽  
Passive Acoustic ◽  
Positioning Algorithm ◽  
Acoustic Positioning

A new acoustic positioning method for Autonomous Underwater Vehicles (AUV) that uses a single underwater hydrophone is proposed in this paper to solve problems of Long Baseline (LBL) array laying and communication synchronisation problems among all hydrophones in the traditional method. The proposed system comprises a Strapdown Inertial Navigation System (SINS), a single hydrophone installed at the bottom of the AUV and a single underwater sound source that emits signals periodically. A matrix of several virtual hydrophones is formed with the movement of the AUV. In every virtual LBL window, the time difference from the transmitted sound source to each virtual hydrophone is obtained by means of a Smooth Coherent Transformation (SCOT) weighting cross-correlation in the frequency domain. Then, the recent location of the AUV can be calculated. Simulation results indicate that the proposed method can effectively compensate for the position error of SINS. Thus, the positioning accuracy can be confined to 2 m, and the method achieves good applicability. Compared with traditional underwater acoustic positioning systems, the proposed method can provide great convenience in engineering implementation and can reduce costs.

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