Acoustical Imaging

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. Front Matter....Pages i-xii Inverse Solutions for Multiple Scattering in Inhomogeneous Acoustic Media....Pages 1-14 A Filtered Backpropogation Algorithm for Fan Beam Diffraction Tomography....Pages 15-15 Fourier Domain Reconstruction Methods with Application to Diffraction Tomography....Pages 17-30 Image Reconstruction from Limited Projections Using the Angular Periodicity of the Fourier Transform of the Radon Transforms of an Object....Pages 31-42 Multifrequency Diffraction Tomography....Pages 43-56 The Inverse Acoustical Scattering Problem for Layered Media in the Presence of Broad-Band Acoustic Noise and with Limited Transducer Bandwidth....Pages 57-73 Fast Iterative Algorithms for Inverse Scattering Solutions of the Helmholtz and Riccati Wave Equations....Pages 75-87 Acoustical Imaging/NDE of Complex Geometries Using Refraction and Reflection Transmission Techniques in Acoustic Microscopy....Pages 89-89 Computer-assisted Tomographic Acoustic Microscopy for Subsurface Imaging....Pages 91-105 The Origin of Grain Contrast in the Scanning Acoustic Microscope....Pages 107-118 Detection of Surface-Breaking Cracks in the Acoustic Microscope....Pages 119-128 Description of the Pulsed Acoustic Field of a Linear Diagnostic Ultrasound Array Using a Simple Approximate Expression....Pages 129-145 Cross-Sectional Measurements and Extrapolations of Ultrasonic Fields....Pages 147-147 Spectrum of Echo Scattered by Simple Object Placed at Focal Plane of Ultrasonic Transducer....Pages 149-162 Measurement and Simulation of the Scattering of Ultrasound by Penetrable Cylinders....Pages 163-178 Fresnel Approximation in the Non Paraxial Case and in Absorbing Media....Pages 179-192 Material Characterization by Acoustic Line-focus Beam....Pages 193-202 Ultrasonic Velocity Spatial Distribution Analysis of Biological Materials with the Scanning Laser Acoustic Microscope....Pages 203-216 Diffraction of Ultrasound by Soft Tissues:The Inhomogeneous Continuous Model....Pages 217-231 Tissue Information from Ultrasound Scattering....Pages 233-245 Stable Impedance Profile Reconstruction by Spike Train Approximation....Pages 247-256 Golay Codes for Simultaneous Multi-mode Ultrasonic Imaging....Pages 257-271 Spectral Equalisation: A Signal Processing Technique to Increase Pulse-Echo Signal Bandwidth....Pages 273-291 The Modified Discrete Wigner Distribution and its Application to Acoustic Well Logging....Pages 293-313 Two Dimensional Statistical Analysis of Synthetically Focused Images....Pages 315-327 Acoustical Imaging Techniques Applied to General Transducer Design....Pages 329-343 Fresnel Zone Plate and Fresnel Phase Plate Patterns for Acoustic Transducers....Pages 345-355 A New Technique for Realizing Annular Arrays or Complex Shaped Transducers....Pages 357-368 A Hybrid Trapped Energy Mode Transducer Array....Pages 369-379 Annular Surface Wave Transducer for Medical Imaging....Pages 381-395 Acoustic Spectral Interferometry: A New Method for Sonic Velocity Determination....Pages 397-408 Thermoacoustic Imaging Induced by Deeply Penetrating Radiation....Pages 409-427 Observation of Acoustic Signals from a Phantom in an 18 MeV Electron Beam for Cancer Therapy....Pages 429-434 Holographic Imaging System Using Wideband Chirped Ultrasound....Pages 435-445 Real-Time Two-Dimensional Doppler Flow Mapping Using Auto-Correlation....Pages 447-460 Imaging of the Ultrasonic Velocity and Reflection Properties of Objects by a C-Scan Method....Pages 461-475 Improvement and Quantitative Assessment of B-mode Images Produced by Annular Array/Cone Hybrids....Pages 477-477 Image Interpolation for Real-Time Compound Dual Sector Scans....Pages 479-492 A Digital Pulse-Echo System Based on Acoustic Inversion....Pages 493-493 A Dual B-scan for Attenuation Acoustical Imaging....Pages 495-499 In-Situ Silt Density Measurements Using a Broadband Parametric Sound Source....Pages 501-512 Computer-Aided Imaging with Optically-Scanned Acoustic Transducers....Pages 513-523 Simulation of Imaging Systems for Underwater Viewing....Pages 525-535 Imaging of Cluttered Targets in Coloured Absorptive Media....Pages 537-548 Seismic Tomography Applied to Surface Wave Analysis....Pages 549-563 Application of Acoustical Holography to Noise Suppression....Pages 565-579 Probabilistic Image Reconstruction Using Experimental Ultrasonic Data....Pages 581-589 Erratum to: Application of Acoustical Holography to Noise Suppression....Pages 591-591 Back Matter....Pages 607-619