Download or read book An Underwater Acoustic Imaging System written by Michael John Kolar and published by . This book was released on 1971 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental underwater acoustic imaging system has been designed and built. Operating at 650 KHz, real time acoustic images are obtainable. Using both geometrical optics and Fourier optics, the theory of image formation and resolution is presented. Other factors affecting image quality and system acuity are also discussed. System components include a 650 KHz lead-zirconate-titanate (PZT) illuminating transducer, and 01.4 Plexiglas acoustic converging lens, an 81 element mosaic PZT receiving transducer which is resonant at about 650 KHz, 81 amplifiers, a scanning and synchronizing system, and a display oscilloscope. Acoustic energy reflected by the target object is collected by the lens and focused onto the image receiving transducer, which is located in the image plane. The image, appearing as a spatial acoustic pressure distribution in the image plane, is sampled by the 81 element receiver, The 81 image element voltages are amplified and sequentially transmitted to the Z-axis input of an oscilloscope. Each channel amplifier is switched, in sequence, by solid state logic switches located in the scanning circuit. The scanning circuit drives the oscilloscope in a nine line TV type raster scan. If an image element is insonified, a bright spot corresponding to the image element is lighted on the oscilloscope display. The receiving system has a measured sensitivity threshold of 3 x 10−10 watts/cm2 and a measured system resolution of approximately 2. 1°. Real time images of simple styrofoam targets are displayed.
Download or read book HYDROCON ACOUSTIC IMAGING SYSTEM written by Lowell A. Noble and published by . This book was released on 1965 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the results of an investigation to develop and demonstrate the feasibility of a new underwater acoustic imaging system using the HYDROCON principle. This new system would substantially extend the underwater detection capability wherever the conventional sonar and optical techniques are not applicable. The more important applications of this system would be in seeing under water over longer distances than are possible with ordinary light, especially where the degree of resolution achieved with optical vision is not needed but where it should be better than that achievable by sonar techniques. Such a system could be important for searching for lost objects under water, underwater rescue missions, piloting of submarines in mined or hazardous waters, oceanography, and classification. A breadboard system was completed and the over-all characteristics were observed experimentally. This was accomplished by using an ultrasonic transmitter, a focusing system to form the acoustic image, and a mosaic array of piezoelectric transducers connected to a specially designed image converter tube for transforming this acoustic image into a visual display. (Author).
Download or read book Sound Images of the Ocean written by Peter Wille and published by Springer Science & Business Media. This book was released on 2005-12-06 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sound Images of the Ocean is the first comprehensive overview of acoustic imaging applications in the various fields of marine research, utilization, surveillance, and protection. The book employs 400 sound images of the sea floor and of processes in the sea volume, contributed by more than 120 marine experts from 22 nations.
Download or read book Underwater Acoustics written by Richard P. Hodges and published by John Wiley & Sons. This book was released on 2011-06-28 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offering complete and comprehensive coverage of modern sonar spectrum system analysis, Underwater Acoustics: Analysis, Design and Performance of Sonar provides a state-of-the-art introduction to the subject and has been carefully structured to offer a much-needed update to the classic text by Urick. Expanded to included computational approaches to the topic, this book treads the line between the highly theoretical and mathematical texts and the more populist, non-mathematical books that characterize the existing literature in the field. The author compares and contrasts different techniques for sonar design, analysis and performance prediction and includes key experimental and theoretical results, pointing the reader towards further detail with extensive references. Practitioners in the field of sonar design, analysis and performance prediction as well as graduate students and researchers will appreciate this new reference as an invaluable and timely contribution to the field. Chapters include the sonar equation, radiated, self and ambient noise, active sonar sources, transmission loss, reverberation, transducers, active target strength, statistical detection theory, false alarms, contacts and targets, variability and uncertainty, modelling detections and tactical decision aids, cumulative probability of detection, tracking target motion analysis and localization, and design and evaluation of sonars
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 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 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 0 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).
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 2002-08-31 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Underwater Acoustic Digital Signal Processing and Communication Systems describes new design and development methodologies in underwater acoustic signal processing. The emphasis is on experimental efforts and modern DSP implementations. The book assembles a number of contributions from authors who have contributed significantly to the field. The topics cover a broad range of underwater acoustic signal processing applications: underwater wireless communciations, array processing for mapping, detection and localization of objects, biotelemetry, speech processing for divers, acoustic imaging, and use of neural networks for underwater signal processing.
Download or read book Sonar and Underwater Acoustics written by Jean-Paul Marage and published by John Wiley & Sons. This book was released on 2013-02-07 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sonar and Underwater Acoustics brings together all the concepts necessary for designers and users of sonar systems. Unlike other books on this subject, which are often too specialized, this book is accessible to a wider audience. The first part focuses on the acoustic environment, antenna structures, and electric acoustic interface. The latter provides knowledge required to design, as well as the development and implementation of chain processes for an active sonar from the conditioning input to output processing. The reader will find a comprehensive range of all problems encountered in underwater acoustics for a sonar application, from physical phenomena governing the environment and the corresponding constraints, through to the technical definition of transducers and antennas, and the types of signal processing involved. In one section, measures in underwater acoustics are also proposed.
Download or read book Underwater Acoustic Imaging written by David Graham Blair and published by . This book was released on 2000 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustical Imaging written by M. Kaveh and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 589 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume constitutes the proceedings of the Thirteenth Inter national Symposium on Acoustical Imaging which was held in Minneapolis, Minnesota during October 26-28, 1983. Forty-eight research papers were presented during the meeting by researchers from twelve countries, again demonstrating the true international character of these meetings. Of these presentations this volume contains forty-two complete manuscripts. The abstracts for addi tional papers that were not available at publication time are also included. According to the recent tradition of these symposia an inter disciplinary program under the general theme of acoustical imaging was organized. This can clearly be observed from the wide range of topics and approaches contained in the following manuscripts. There are papers of mathematical nature dealing with the basis of image formation and algorithms for digitally carrying out specific imaging tasks. One finds manuscripts dealing with the design and construction of imaging transducers as well as complete imaging systems. Applications include medical imaging and nondestructive testing, seismic and underwater imaging. This volume, therefore, should be of interest to active researchers in acoustical imaging as a report on current research and to workers in signal process ing, sonics and ultrasonics who are interested in exploring the diverse areas of application for their fields of interest. These proceedings are organized in seven topical sections, paral leling the sessions of the conference. These are: Inversion and Tomography, Microscopy, Scattering and Propagation, Tissue and Material Characterization, Signal Processing, Transducers and Arrays, Imaging Systems and Special Techniques.
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 An Experimental Ultrasonic Image System For Underwater Vision written by Kenneth George Robinson and published by . This book was released on 1967 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation of acoustic imaging in water is made at an ultrasonic frequency of 455 KHz. Using optical principles, the theory of image formation and resolution are discussed. The range capability of such a system is predicted by the use of underwater acoustic theory. The apparatus consists of a basic imaging system that provides a set of d.c. voltages, proportional to sound intensity at points in the image plane, to be applied to a visual display system. Such a display will present a two dimensional image of an insonified underwater target. This study differs from previous work done in underwater acoustic imaging, in that the image conversion process will lend itself to the application of integrated circuits. (Author).
Download or read book An Experimental Ultrasonic Image System for Underwater Vision written by and published by . This book was released on 1967 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation of acoustic imaging in water is made at an ultrasonic frequency of 455 KHz. Using optical principles, the theory of image formation and resolution are discussed. The range capability of such a system is predicted by the use of underwater acoustic theory. The apparatus consists of a basic imaging system that provides a set of d.c. voltages, proportional to sound intensity at points in the image plane, to be applied to a visual display system. Such a display will present a two dimensional image of an insonified underwater target. This study differs from previous work done in underwater acoustic imaging, in that the image conversion process will lend itself to the application of integrated circuits. (Author).
Download or read book An Introduction to Underwater Acoustics written by Xavier Lurton and published by Springer Science & Business Media. This book was released on 2002 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented in a clear and concise way as an introductory text and practical handbook, the book provides the basic physical phenomena governing underwater acoustical waves, propagation, reflection, target backscattering and noise. It covers the general features of sonar systems, transducers and arrays, signal processing and performance evaluation. It provides an overview of today's applications, presenting the working principles of the various systems. From the reviews: "Presented in a clear and concise way as an introductory text and practical handbook, the book provides the basic physical phenomena governing underwater acoustical waves, propagation, reflection, target backscattering and noise. ⦠It provides an overview of todayâs applications, presenting the working principles of the various systems." (Oceanis, Vol. 27 (3-4), 2003) "This book is a general survey of Underwater Acoustics, intended to make the subject âas easily accessible as possible, with a clear emphasis on applications.â In this the author has succeeded, with a wide variety of subjects presented with minimal derivation ⦠. There is an emphasis on technology and on intuitive physical explanation ⦠." (Darrell R. Jackson, Journal of the Acoustic Society of America, Vol. 115 (2), February, 2004) "This is an exciting new scientific publication. It is timely and welcome ⦠. Furthermore, it is up to date and readable. It is well researched, excellently published and ranks with earlier books in this discipline ⦠. Many persons in the marine science field including acousticians, hydrographers, oceanographers, fisheries scientists, engineers, educators, students ⦠and equipment manufacturers will benefit greatly by reading all or part of this text. The author is to be congratulated on his fine contribution ⦠." (Stephen B. MacPhee, International Hydrographic Review, Vol. 4 (2), 2003)
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 Underwater Acoustic Image Processing written by Reza Javidan and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic is the study of sound. Underwater acoustic plays an important role in understanding the undersea environment. Today, sonar systems become a common acoustic-based technology for underwater exploration. Signals reflected to the sonar systems can be used to construct an image in a raster scan structure. Such imaging sonars provide near-photographic images of underwater areas, even in zero visibility water. Image processing approaches for sonar systems are the main subject of this book. Underwater acoustic image processing consists of image acquisition, pre-processing, image feature extraction, image segmentation, and image classification. We developed new algoruthms and methods in all of the above categories. Due to highly textured appearance of sonar images, texture analysis methods become a common choice for acoustic images. This Book also discusses algorithms for textural feature extraction and classification applied to supervised segmentation of multi-textured images using wavelet and contourlet transforms. All the proposed schemes are compared with commonly used texture segmentation and classification methods on different image sets to show the fidelity of our methods.
