Doubly resonant underwater acoustic transducer for long distance sound propagation

Due to the strong absorption and attenuation of electromagnetic waves by water, radio communications and global positioning systems are lacking in the deep-sea environment. Therefore, underwater long-distance communications, positioning, detection and other functions depend on acoustic technology. In order to realize the above functions, the acoustic system of the Fendouzhe human occupied vehicle (HOV) is composed of eight kinds of sonars and sensors, which is one of the core systems of manned submersible. Based on the Jiaolong/Shenhai Yongshi HOVs, the acoustic system of the Fendouzhe HOV has been developed. Compared with the previous technology, there are many technical improvements and innovations: 10,000-m underwater acoustic communication, 10,000-m underwater acoustic positioning, multi-beam forward-looking imaging sonar, an integrated navigation system, etc. This study introduces the structure of the acoustic system of the Fendouzhe HOV and the technical improvements compared with the Jiaolong/Shenhai Yongshi HOVs. The results of the acoustic system are illustrated by the 10,000-m sea trails in the Mariana Trench from October to December 2020.

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Development of Automated Measurement Setup for Characterizing Underwater Acoustic Transducers

Marine Technology Society Journal ◽

10.4031/mtsj.50.6.9 ◽

2016 ◽

Vol 50 (6) ◽

pp. 69-75

Author(s):

Amirthalingam Malarkodi ◽

Peddinti SSR Sridhar ◽

Ganesan Latha

Keyword(s):

Accurate Determination ◽

Motion Controller ◽

Report Generation ◽

Underwater Acoustic ◽

Acoustic Transducers ◽

Acoustic Transducer ◽

Measurement Results ◽

Computer Based ◽

Calibration Program

AbstractAccurate determination of sensitivity and directivity is important for any underwater acoustic transducer. In this work, an automatic measuring platform was designed and implemented for characterizing underwater acoustic transducers. The overall hardware setup includes a PXI (PCI Extensions for Instrumentation)-based data acquisition system, computer-based controller module, motion controller module, and LabVIEW-based automatic calibration program. The system performs a sequence of operations automatically and achieves synchronous control of transmission and acquisition of real-time acoustic signals as well as processing, recording, and report generation. This measurement platform can be utilized for characterizing any type of acoustic transducer for its receiving sensitivity, transmitting response, and directivity measurement as per IEC60565 standard. The measurement results for RESON TC4034 and RESON TC 2080 transducers are presented and the results show that the system is able to carry out accurate calibration and characterization of any underwater acoustic transducer. Sources of uncertainty for calibration are also presented with the confidence level of approximately 95%.

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Multi-fluid cavity underwater acoustic transducer

The Journal of the Acoustical Society of America ◽

10.1121/1.4920913 ◽

2015 ◽

Vol 137 (4) ◽

pp. 2440-2440

Author(s):

Yongjie Sang ◽

Yu Lan

Keyword(s):

Underwater Acoustic ◽

Acoustic Transducer

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Efficiency measurement of an underwater acoustic transducer using LabVIEW

2015 IEEE Underwater Technology (UT) ◽

10.1109/ut.2015.7108304 ◽

2015 ◽

Author(s):

P S S R Sridhar ◽

A Malarkodi

Keyword(s):

Efficiency Measurement ◽

Underwater Acoustic ◽

Acoustic Transducer

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The Application of RAKE Receiving Technology in the Underwater SS Communication

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.513-517.4248 ◽

2014 ◽

Vol 513-517 ◽

pp. 4248-4252 ◽

Cited By ~ 1

Author(s):

Yun Hang Zhu ◽

Zhi Hui Deng

Keyword(s):

High Speed ◽

Simulation Analysis ◽

High Reliability ◽

Underwater Acoustic Communication ◽

Technical Solution ◽

Acoustic Transmission ◽

Long Distance ◽

Underwater Acoustic ◽

Underwater Wireless Communication ◽

Spreading Spectrum

In recent years, the strategic significance of the oceans is growing as well as its research and development needs. The underwater wireless communication is becoming more and more important. The underwater acoustic communication is one of the few mediums which can conduct the underwater transmission over a long distance, and the multipath effect is the major obstacle of affecting the systems high speed and high reliability. The characteristics of underwater acoustic fading and coherent multi-path channel are studied, and the model of underwater acoustic spreading spectrum (SS) communication system is established. The affect of coding technique on the systems performance are analyzed in detail. The improved RAKE receiving technical solution is put forward, whose simulation analysis and data in different combining ways are given. It is proved that the scheme can better solve the problem of multipath interference in underwater acoustic transmission.

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