Advanced Signal Processing Techniques For Underwater Acoustic Transmission Using Steerable Transducer Arrays
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Advanced Signal Processing Techniques For Underwater Acoustic Transmission Using Steerable Transducer Arrays
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Author : Wichian Ooppakaew
language : en
Publisher:
Release Date : 2012
Advanced Signal Processing Techniques For Underwater Acoustic Transmission Using Steerable Transducer Arrays written by Wichian Ooppakaew and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012 with categories.
The main objective of this research is to design and implement an eight-hydrophone transmitter array for generating bipolar acoustic pulses mimicking those produced by cosmogenic neutrino interaction in sea water. In addition, the research was conducted as part of the ACoRNE collaboration. The work initially investigated a single hydrophone system. Due to the nature of hydrophone, the acoustic output signal does not precisely follow a given driving voltage input. Hence signal processing techniques and hydrophone modelling were applied. A bipolar acoustic generation module was built using 8-bit PIC microcontrollers for processing and control. A NI USB-6211 National Instruments commercial module was used for validation of results. The modelling was compared to experimental data generated in a water tank, showing excellent agreement. This single hydrophone instrument was deployed at the Rona array in 2008. Both 10 kHz and 23 kHz pulses were injected, whilst seven hydrophones at Rona site were chosen as the receiver hydrophone array. Signal processing techniques were applied to identify these pulses. The result showed that the triggered pulses can be detected and identified at Rona over a distance of a few hundred metres. A model for an eight-hydrophone transmission linear array system for the ANTARES site was developed. The simulation showed that the eight hydrophones arranged over an eight-metre spacing structure can mimic the anticipated pancake behaviour predicted from neutrino-induced showers as well as generating the acoustic bipolar pulse shape of sufficient amplitude for detection at ANTARES. An eight-channel arbitrary waveform generator module was designed and built using 16-bit dsPIC microcontrollers. Signal Processing techniques were again applied to calibrate the hydrophone transmitter array. The behaviour of an acoustic transducer array was examined in a laboratory water tank to study the shape and direction of such a signal in water. The results were validated against a PXI-6713 commercial module. Excellent agreement was achieved. Finally, the system was deployed at the ANTARES site in September 2011. A range of test signals including 23 kHz bipolar pulses, sine signals and orthogonal signals were injected into seawater to simulate neutrino interactions and investigate signal coding. Signal processing techniques were applied to the data deployed in order to recognise the signals emitted. However, the vessel was far away from the position planned (c 1km), hence the signal received was too weak and no signal was detected. However, the deployed data is still very useful in order to study the noise background of seawater and much has been learned for future sea campaigns.
Advanced Signal Processing Techniques For Underwater Acoustic Communication Networks
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Author : Chunshan Liu
language : en
Publisher:
Release Date : 2011
Advanced Signal Processing Techniques For Underwater Acoustic Communication Networks written by Chunshan Liu and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011 with categories.
In this thesis, we develop and investigate novel signal processing techniques for underwater acoustic communication networks. Underwater acoustic channels differ from radio communication channels in the lower speed of signal propagation, richer and often sparse multipath arrivals, and more severe Doppler effect. Therefore, many signal processing techniques developed for radio communications may not work equivalently well for underwater acoustic channels. To investigate signal processing techniques in underwater acoustics, efficient simulation of signal transmission is required. Specifically, there is requirement for accurate simulation of doubly-selective underwater channels for different acoustic environments. In this thesis, a low-complexity channel simulator has been developed for scenarios with moving transmitter/receiver. The simulator is based on efficient generation of time-varying channel impulse response obtained using interpolation over a set of waymark impulse responses for a relatively small number of sampling points on the transmitter/receiver trajectory. The waymark impulse responses are generated using an acoustic field computation method, which is the most computationally expensive part of the simulator. To reduce the trajectory sampling rate, and thus, to reduce the complexity of the field computation, an approach for adjusting the time-varying multipath delays has been developed. For setting the trajectory sampling interval, a simple rule has been proposed, based on the waveguide invariant theory. To further reduce the simulator complexity, local spline interpolation is exploited. The developed simulator has been verified by comparing the simulated data with data from real ocean experiments. In particular, applying simulated data to an OFDM modem shows similar performance with that obtained from the data of a deep water experiment. In communication networks, knowledge of positions of communication nodes is important for improving the system performance. A multi-source localization technique has been proposed based on the matched field (MF) processing. The technique locates the nodes by solving a set of basis pursuit de-noising (BPDN) problems corresponding to a set of source frequencies. An efficient technique combining the homotopy approach and coordinate descent search has been developed to solve the BPDN problem. Further reduction in the complexity has been achieved by applying a position grid refinement method. Verified using simulated data generated by the proposed simulator and data from real experiment, the proposed technique outperforms other MF techniques in resolving sources positioned closely to each other, tolerance to noise and capability of locating multiple sources. To provide reliable localization based on MF techniques, accurate knowledge of the underwater acoustic environment is essential. However, such knowledge is not always available. Estimating uncertain environmental parameters can be achieved using MF inversion techniques. This requires solving a global optimization problem. Several global optimization algorithms have been investigated and an algorithm combining the simulated annealing and downhill simplex method has been applied for estimating the sound speed profile in a deep water scenario. Accurate MF localization results have been demonstrated when using the estimated sound speed profile. A very important task of communication receivers is accurate channel estimation. The knowledge of node positions and the environment can be exploited for enhancing the channel estimation accuracy and reducing the estimation complexity. This knowledge can be used to define the structure of the channel impulse response, such as the multipath spread and the sparsity. A channel estimator exploiting the channel sparsity estimated from the node positions has been proposed and investigated. The sparse taps of the channel impulse response are identified by solving a BPDN problem. The estimator employs an iterative tap-by-tap processing and uses local splines to interpolate the time-varying tap coefficients. This allows reduction in the complexity and memory requirement, whereas providing a high estimation accuracy.
Digital Sonar Design In Underwater Acoustics
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Author : Qihu Li
language : en
Publisher: Springer Science & Business Media
Release Date : 2012-03-05
Digital Sonar Design In Underwater Acoustics written by Qihu Li and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-03-05 with Science categories.
"Digital Sonar Design in Underwater Acoustics Principles and Applications" provides comprehensive and up-to-date coverage of research on sonar design, including the basic theory and techniques of digital signal processing, basic concept of information theory, ocean acoustics, underwater acoustic signal propagation theory, and underwater signal processing theory. This book discusses the general design procedure and approaches to implementation, the design method, system simulation theory and techniques, sonar tests in the laboratory, lake and sea, and practical validation criteria and methods for digital sonar design. It is intended for researchers in the fields of underwater signal processing and sonar design, and also for navy officers and ocean explorers. Qihu Li is a professor at the Institute of Acoustics, Chinese Academy of Sciences, and an academician of the Chinese Academy of Sciences.
Aspects Of Signal Processing With Emphasis On Underwater Acoustics Part 2
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Author : G. Tacconi
language : en
Publisher: Springer
Release Date : 1977-04-30
Aspects Of Signal Processing With Emphasis On Underwater Acoustics Part 2 written by G. Tacconi and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 1977-04-30 with Technology & Engineering categories.
This paper describes the results of current research at DREA in which techniques of optimum array processing are being applied to active sonar. We are presenting these results at the Advanced Study Institute in order to illustrate some actual applications for such processing and to point out some of the practical considerations which arise in real systems. In particular, the paper concerns the problems which arise when the individual sensor elements have a complicated directivity pattern themselves. This is a common phenomenon in active systems where the receiving sensors are complex resonant structures and are housed in a dome or towed body presenting various baffling and diffraction effects. Most treatments of array processing consider ideal elements which have well behaved directivity properties and are transparent to the field. The results of this paper show that where these properties are not met, careful in situ array measurements are required, and even with such measurements practical array gains may not be as good as predictions based on ideal sensors.
Advanced Signal Processing Techniques For Underwater Acoustic Communiction Networks
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Author :
language : en
Publisher:
Release Date : 2011
Advanced Signal Processing Techniques For Underwater Acoustic Communiction Networks written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011 with categories.
Underwater Acoustic System Analysis
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Author : William S. Burdic
language : en
Publisher: Peninsula Publishing
Release Date : 2002
Underwater Acoustic System Analysis written by William S. Burdic and has been published by Peninsula Publishing this book supported file pdf, txt, epub, kindle and other format this book has been release on 2002 with Technology & Engineering categories.
Underwater Aacoustic System Analysis provides a comprehensive exploration of underwater acoustics, acoustic signal generation, and acoustic signal processing for the practicing systems analyst and systems engineer. This second edition, first published in 1991, contains all the valuable information in the earlier edition plus a detailed discussion of of adaptive processing as applied to spatial filtering. Highlights of the book are: * Generation and propagation of compressional acoustic acoustic waves in the ocean * narrowband signatures of surface ships caused by cavitating propeller blades and diesel engine firing * Optimization of signal-to-noise ratio and spatial reslution in the presence of multiple acoustic signals * Ambient noise in the ocean, and * Examples of sytem performance analysis
Underwater Acoustic Networking Techniques
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Author : Roald Otnes
language : en
Publisher: Springer Science & Business Media
Release Date : 2012-01-19
Underwater Acoustic Networking Techniques written by Roald Otnes and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-01-19 with Technology & Engineering categories.
This literature study presents an overview of underwater acoustic networking. It provides a background and describes the state of the art of all networking facets that are relevant for underwater applications. This report serves both as an introduction to the subject and as a summary of existing protocols, providing support and inspiration for the development of network architectures.
Ofdm For Underwater Acoustic Communications
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Author : Sheng Zhou
language : en
Publisher: John Wiley & Sons
Release Date : 2014-03-21
Ofdm For Underwater Acoustic Communications written by Sheng Zhou and has been published by John Wiley & Sons this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014-03-21 with Science categories.
A blend of introductory material and advanced signal processing and communication techniques, of critical importance to underwater system and network development This book, which is the first to describe the processing techniques central to underwater OFDM, is arranged into four distinct sections: First, it describes the characteristics of underwater acoustic channels, and stresses the difference from wireless radio channels. Then it goes over the basics of OFDM and channel coding. The second part starts with an overview of the OFDM receiver, and develops various modules for the receiver design in systems with single or multiple transmitters. This is the main body of the book. Extensive experimental data sets are used to verify the receiver performance. In the third part, the authors discuss applications of the OFDM receiver in i) deep water channels, which may contain very long separated multipath clusters, ii) interference-rich environments, where an unintentional interference such as Sonar will be present, and iii) a network with multiple users where both non-cooperative and cooperative underwater communications are developed. Lastly, it describes the development of a positioning system with OFDM waveforms, and the progress on the OFDM modem development. Closely related industries include the development and manufacturing of autonomous underwater vehicles (AUVs) and scientific sensory equipment. AUVs and sensors in the future could integrate modems, based on the OFDM technology described in this book. Contents includes: Underwater acoustic channel characteristics/OFDM basics/Peak-to-average-ratio control/Detection and Doppler estimation (Doppler scale and CFO)/Channel estimation and noise estimation/A block-by-block progressive receiver and performance results/Extensions to multi-input multi-output OFDM/Receiver designs for multiple users/Cooperative underwater OFDM (Physical layer network coding and dynamic coded cooperation)/Localization with OFDM waveforms/Modem developments A valuable resource for Graduate and postgraduate students on electrical engineering or physics courses; electrical engineers, underwater acousticians, communications engineers
High Resolution Spatial Processing In Underwater Acoustics
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Author : Ronald A. Wagstaff
language : en
Publisher:
Release Date : 1985
High Resolution Spatial Processing In Underwater Acoustics written by Ronald A. Wagstaff and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1985 with Beamforming categories.
Aspects Of Signal Processing With Emphasis On Underwater Acoustics Part 2
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Author : G. Tacconi
language : en
Publisher: Springer
Release Date : 1977-04-30
Aspects Of Signal Processing With Emphasis On Underwater Acoustics Part 2 written by G. Tacconi and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 1977-04-30 with Technology & Engineering categories.
This paper describes the results of current research at DREA in which techniques of optimum array processing are being applied to active sonar. We are presenting these results at the Advanced Study Institute in order to illustrate some actual applications for such processing and to point out some of the practical considerations which arise in real systems. In particular, the paper concerns the problems which arise when the individual sensor elements have a complicated directivity pattern themselves. This is a common phenomenon in active systems where the receiving sensors are complex resonant structures and are housed in a dome or towed body presenting various baffling and diffraction effects. Most treatments of array processing consider ideal elements which have well behaved directivity properties and are transparent to the field. The results of this paper show that where these properties are not met, careful in situ array measurements are required, and even with such measurements practical array gains may not be as good as predictions based on ideal sensors.