Download or read book Underwater Acoustic Imaging Rapid Signal Processing written by and published by . This book was released on 1998 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: An innovation program to develop an underwater acoustic imaging system able to resolve objects down to millimetre resolution in turbid waters is under way. The defence need is for the identification of minelike objects. This report reviews options for the signal processing or beamforming stage of the program. An image consisting of 3x10 to the 9th power voxels (volume pixels) could be formed by a summation of the voltages from 4000 sensor elements, each taken from the element's voltage stream at the appropriate time. With a suitable allowance (factor of 9) for calculating the time delays, it appears at first sight that 9x1.2x10 to the 13th power operations would be required. The problem is to calculate a three-dimensional image of adequate quality in the shortest time at the least cost. A hierarchical structure of options is developed in an attempt to capture all possibilities. At the top level, three approaches are identified. First, the use of appropriate hardware, such as computers with parallelism. Second, a reduction in the number of operations (a software' solution). And third, the defining of a suitable reduced goal, which appears to come down to the imaging of a subvolume of the original volume that contains the object of interest. Each of these three approaches is divided into suboptions; these are discussed in detail to bring out difficulties and advantages.

Download or read book Underwater Acoustic Imaging Rapid Signal Processing written by and published by . This book was released on 1998 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: An innovation program to develop an underwater acoustic imaging system able to resolve objects down to millimetre resolution in turbid waters is under way. The defence need is for the identification of minelike objects. This report reviews options for the signal processing or beamforming stage of the program. An image consisting of 3x10 to the 9th power voxels (volume pixels) could be formed by a summation of the voltages from 4000 sensor elements, each taken from the element's voltage stream at the appropriate time. With a suitable allowance (factor of 9) for calculating the time delays, it appears at first sight that 9x1.2x10 to the 13th power operations would be required. The problem is to calculate a three-dimensional image of adequate quality in the shortest time at the least cost. A hierarchical structure of options is developed in an attempt to capture all possibilities. At the top level, three approaches are identified. First, the use of appropriate hardware, such as computers with parallelism. Second, a reduction in the number of operations (a software' solution). And third, the defining of a suitable reduced goal, which appears to come down to the imaging of a subvolume of the original volume that contains the object of interest. Each of these three approaches is divided into suboptions; these are discussed in detail to bring out difficulties and advantages.

Download or read book Underwater Acoustic Digital Signal Processing and Communication Systems written by Robert Istepanian and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: Underwater acoustic digital signal processing and communications is an area of applied research that has witnessed major advances over the past decade. Rapid developments in this area were made possible by the use of powerful digital signal processors (DSPs) whose speed, computational power and portability allowed efficient implementation of complex signal processing algorithms and experimental demonstration of their performance in a variety of underwater environments. The early results served as a motivation for the development of new and improved signal processing methods for underwater applications, which today range from classical of autonomous underwater vehicles and sonar signal processing, to remote control underwater wireless communications. This book presents the diverse areas of underwater acoustic signal processing and communication systems through a collection of contributions from prominent researchers in these areas. Their results, both new and those published over the past few years, have been assembled to provide what we hope is a comprehensive overview of the recent developments in the field. The book is intended for a general audience of researchers, engineers and students working in the areas of underwater acoustic signal processing. It requires the reader to have a basic understanding of the digital signal processing concepts. Each topic is treated from a theoretical perspective, followed by practical implementation details. We hope that the book can serve both as a study text and an academic reference.

Download or read book Underwater Acoustic Signal Processing written by Douglas A. Abraham and published by Springer. This book was released on 2019-02-14 with total page 834 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides comprehensive coverage of the detection and processing of signals in underwater acoustics. Background material on active and passive sonar systems, underwater acoustics, and statistical signal processing makes the book a self-contained and valuable resource for graduate students, researchers, and active practitioners alike. Signal detection topics span a range of common signal types including signals of known form such as active sonar or communications signals; signals of unknown form, including passive sonar and narrowband signals; and transient signals such as marine mammal vocalizations. This text, along with its companion volume on beamforming, provides a thorough treatment of underwater acoustic signal processing that speaks to its author’s broad experience in the field.

Download or read book Underwater Acoustic Data Processing written by Y. T. Chan and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the papers that were accepted for presentation at the 1988 NATO Advanced Study Institute on Underwater Acoustic Data Processing, held at the Royal Military College of Canada from 18 to 29 July, 1988. Approximately 110 participants from various NATO countries were in attendance during this two week period. Their research interests range from underwater acoustics to signal processing and computer science; some are renowned scientists and some are recent Ph.D. graduates. The purpose of the ASI was to provide an authoritative summing up of the various research activities related to sonar technology. The exposition on each subject began with one or two tutorials prepared by invited lecturers, followed by research papers which provided indications of the state of development in that specific area. I have broadly classified the papers into three sections under the titles of I. Propagation and Noise, II. Signal Processing and III. Post Processing. The reader will find in Section I papers on low frequency acoustic sources and effects of the medium on underwater acoustic propagation. Problems such as coherence loss due to boundary interaction, wavefront distortion and multipath transmission were addressed. Besides the medium, corrupting noise sources also have a strong influence on the performance of a sonar system and several researchers described methods of modeling these sources.

Download or read book Acoustic Signal Processing for Ocean Exploration written by J.M.F Moura and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 671 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic Signal Processing for Ocean Explortion has two major goals: (i) to present signal processing algorithms that take into account the models of acoustic propagation in the ocean and; (ii) to give a perspective of the broad set of techniques, problems, and applications arising in ocean exploration. The book discusses related issues and problems focused in model based acoustic signal processing methods. Besides addressing the problem of the propagation of acoustics in the ocean, it presents relevant acoustic signal processing methods like matched field processing, array processing, and localization and detection techniques. These more traditional contexts are herein enlarged to include imaging and mapping, and new signal representation models like time/frequency and wavelet transforms. Several applied aspects of these topics, such as the application of acoustics to fisheries, sea floor swath mapping by swath bathymetry and side scan sonar, autonomous underwater vehicles and communications in underwater are also considered.

Download or read book Underwater Acoustics and Signal Processing written by L. Bjørnø and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 730 pages. Available in PDF, EPUB and Kindle. Book excerpt: The comprehensive research activity around the World in the fields of Underwater Acoustics and Signal Processing being strongly supported by new experimental technique and equipment and by the parallel fast developments in computer technology and solid state devices, which has led to a rapidly reducing cost of digital processing thus enabling more complex processing to be carried out economically, emphasize how necessary it is at intervals of a few years through a NATO Advanced Study Institute (NATO ASI) and guided by leading experts to study the conquests in the fields of Underwater Acoustics and Signal Processing. This need of study is moreover stressed by the interdisciplina rity of Underwater Acoustics and Signal Processing, where a strong impact from other branches of science, - Geophysics, Radioastronomy, Bioengineering, Telecommunication, Seismology, Space Research etc. - is taking place, which makes it an extre mely difficult task for scientists to follow-up the development in all its phases and to preserve the general view of its rapid ly increasing number of possibilities. The present Proceedings of the NATO ASI held in Copenhagen during August 1980 join the series of proceedings of NATO summer schools on Underwater Acoustics and Signal Processing held during the past 20 years. The equality and the fusion of the individual research fields of Underwater Acoustics and Signal Processing and the separate introduction of advanced research results from other scientific areas related to underwater acoustics such as transducers characterize the subject matter of this NATO ASI.

Download or read book Channel Modeling and Threshold Signal Processing in Underwater Acoustics written by David Middleton and published by . This book was released on 1986 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Underwater Acoustic System Analysis written by William S. Burdic and published by Peninsula Publishing. This book was released on 2002 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Acoustical Imaging written by Woon Siong Gan and published by John Wiley & Sons. This book was released on 2012-05-11 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: The technology of acoustical imaging has advanced rapidly over the last sixty years, and now represents a sophisticated technique applied to a wide range of fields including non-destructive testing, medical imaging, underwater imaging and SONAR, and geophysical exploration. Acoustical Imaging: Techniques and Applications for Engineers introduces the basic physics of acoustics and acoustical imaging, before progressing to more advanced topics such as 3D and 4D imaging, elasticity theory, gauge invariance property of acoustic equation of motion and acoustic metamaterials. The author draws together the different technologies in sonar, seismic and ultrasound imaging, highlighting the similarities between topic areas and their common underlying theory. Key features: Comprehensively covers all of the important applications of acoustical imaging. Introduces the gauge invariance property of acoustic equation of motion, with applications in the elastic constants of isotropic solids, time reversal acoustics, negative refraction, double negative acoustical metamaterial and acoustical cloaking. Contains up to date treatments on latest theories of sound propagation in random media, including statistical treatment and chaos theory. Includes a chapter devoted to new acoustics based on metamaterials, a field founded by the author, including a new theory of elasticity and new theory of sound propagation in solids and fluids and tremendous potential in several novel applications. Covers the hot topics on acoustical imaging including time reversal acoustics, negative refraction and acoustical cloaking. Acoustical Imaging: Techniques and Applications for Engineers is a comprehensive reference on acoustical imaging and forms a valuable resource for engineers, researchers, senior undergraduate and graduate students.

Download or read book Digital Underwater Acoustic Communications written by Lufen Xu and published by Academic Press. This book was released on 2016-09-16 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Digital Underwater Acoustic Communications focuses on describing the differences between underwater acoustic communication channels and radio channels, discusses loss of transmitted sound in underwater acoustic channels, describes digital underwater acoustic communication signal processing, and provides a comprehensive reference to digital underwater acoustic communication equipment. This book is designed to serve as a reference for postgraduate students and practicing engineers involved in the design and analysis of underwater acoustic communications systems as well as for engineers involved in underwater acoustic engineering. Introduces the basics of underwater acoustics, along with the advanced functionalities needed to achieve reliable communications in underwater environment Identifies challenges in underwater acoustic channels relative to radio channels, underwater acoustic propagation, and solutions Shows how multi-path structures can be thought of as time diversity signals Presents a new, robust signal processing system, and an advanced FH-SS system for multimedia underwater acoustic communications with moderate communication ranges (above 20km) and rates (above 600bps) Describes the APNFM system for underwater acoustic communication equipment (including both civil and military applications), to be employed in active sonar to improve its performance

Download or read book Underwater Real Time 3D Acoustical Imaging written by Cheng Chi and published by Springer. This book was released on 2019-01-22 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the topic of underwater real-time 3-D acoustical imaging covering the theory, algorithms and system design. It summarizes recent advances in wideband and ultra-wideband underwater real-time 3-D acoustical imaging, which will be very useful for developing next-generation systems. Through simulation techniques, readers are able to quickly learn and develop practical underwater real-time 3-D acoustical imaging systems of their own.

Download or read book An Introduction to Underwater Acoustics written by Xavier Lurton and published by Springer. This book was released on 2016-08-23 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sound waves are the only practical means of remote investigation of the sea and its bottom and transmission in seawater. Underwater acoustics has become one of the major technologies used in the exploration and exploitation of the oceans for scientific, industrial, or military/naval purposes. It is widely employed in the fields of ocean engineering, seafloor mapping, defence, oceanography, navigation, and fisheries. Dr Xavier Lurton is a renowned specialist in underwater acoustics. He has worked in this field as a scientist, engineer, project manager and teacher since 1981 and has participated in many scientific projects, systems developments and at-sea cruises. In the second edition of his book, Dr Lurton provides an updated and extended introduction to underwater acoustics, including coverage of the physical processes and their basic modeling, different underwater acoustic systems and their practical applications and a description and assessment of the various technologies. Dr Lurton has extensive experience as a lecturer in undergraduate and postgraduate schools, including naval academies. This book is based on his direct, first-hand experience of the many aspects of underwater acoustics in seas around the world, at the forefront of current research and development efforts.

Download or read book High resolution Spatial Processing in Underwater Acoustics written by Ronald A. Wagstaff and published by . This book was released on 1985 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Underwater Acoustic Imaging written by David Graham Blair and published by . This book was released on 1997 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-resolution underwater acoustic imaging using multi-element arrays implies a large computational load. For a three-dimensional viewing volume resolved into 3x10(exp 9) voxels (volume pixels), with 4000 elements, the computations needed are around 9x(1.2x10(exp 13)) floating-point operations. This report develops one of the more promising options for computing the full image. First, parallel computation is used to deal with the different sensor elements simultaneously, when calculating the address of the appropriate instantaneous voltage at the sensor element-or, equivalently, the calculation of the round-trip distance traveled by the acoustic pulse. This calculation requires, in a typical near-field situation, the computation either of a square root or of a fifth degree polynomial. This polynomial allows increased parallelism. Second, the summation in the beamforming is likewise done with a high degree of parallelism. A machine with the above design, with 10(exp 9) clock cycles per second, would compute the entire image in roughly 6 seconds. Cost and availability are not investigated.

Download or read book Adaptive Methods in Underwater Acoustics written by H.G. Urban and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 763 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NATO Advanced Study Institute on Adaptive Methods in Underwater Acoustics was held on 30 July - 10 August 1984 in LLineburg, Germany. The Institute was primarily concerned with signal processing for underwater appl ica tions. The majority of the presentations, when taken together, yield a definite picture of the present status of understanding of adaptive and high resolution processing, setting out the progress achieved over the past four years together with the major problem areas remaining. Major effort was made to obtain a commensurate contribution of tutorial and advanced research papers. It is my hope that the material in this volume may be equally well suited for students getting an introduction to some of the basic problems in underwater signal processing and for the professionals who may obtain an up-to-date overview of the present state of the art. This might be especially useful in view of the controversy and lack of adequate interrelationships which have marked this rapidly expanding field in the past. Practical reinforcement of this picture is provided by the material concerning digital and optical processing technology, giving some guidance to achievable adaptive and high resolution techniques with current processing devices. The formal programme was extended and detailed by a series of six evening work shops on specific topics, during which informal discussions took place among the participants. Summaries of these workshops are also included in these Proceedings.

Download or read book A Signal Processing Algorithm Based on Multiple Microprocessors for an Underwater Acoustic Imaging System written by Guy Ronald Arthur Vermander and published by . This book was released on 1980 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: An algorithm has been designed to provide near real-time location and classification information to an operator of an underwater acoustic imaging system. The overall system to detect objects buried up to five meters in unconsolidated marine sediments consists of a specialized projector co-located with a five meter receiving line array. This system is described in basic terms together with the principles of the signal processing that extracts information from the scattered acoustic signals. Using simulated objects, the angular resolution and imaging performance of a number of system designs were evaluated. To obtain near real-time execution, the algorithm was optimized and partitioned using parallel, pipeline, and double buffering techniques for independent but synchronized operation on multiple microprocessors. The feasibility of the design approach was experimentally demonstrated using four single board computers in a microcomputer development system. (Author).