Main description:

Volume 15 follows the format of earlier volumes in the series. The contents give the next installment in the varied aspects of acoustical imaging research. On this occasion, some emphasis was placed on the rela tionship of l1nderwater acoustics to acoustical imaging and a volume of papers under the title "Underwater Acoustics Proceedings from the 12th ICA Symposium held in Halifax," will appear at roughly the same time as this volume. There is no duplication in these volumes but they are in terlinked, at least to the extent that papers from common conference sessions appear in one or another volume. An innovation is the review paper presented at the beginning of the volume "A History of Acoustical Imaging," by G Wade. This fairly detailed review comes at a point in time when so much has been achieved and in some cases passed by, that a record of some of the earlier work might help to keep a balance with the large collections of research papers which have appeared in the many volumes.

Contents:

A History of Acoustical Imaging.- Tomography and Image Reconstruction.- Diffraction Tomography with Multiple Scattering.- Arced Backprojection with an Efficient Computation for Ultrasound Reflection Mode Tomography.- Passive Imaging Through Media with Distributed Inhomogeneities Using an Extension of the Phase Closure Technique.- Computation Simplification for High-Speed Acoustical Image Reconstruction.- A Frequency Diversity Method of Reducing Speckle in Wideband Ultrasound Images.- Ultrasonic Phase Tomography for Medical Applications.- Tissue Characterization.- Improved Tissue Characterization Using Scattering Images.- Transient Acoustic Scattering in Dispersive Soft Tissue.- Estimation of Acoustic Attenuation in Diffuse Liver Disease: Can it Be Done With the Zero-Crossing Technique?.- Transducers and Arrays.- Calculation of Transient Radiation Fields from Axial Symmetric Sources.- Pulsed PVDF Transducer Fields - Comparison of Theory and Experiment.- A New Technique for Characterizing Ultrasonic Transducers in Inhomogeneous Media.- Development of an Electromagnetic Acoustic Transducer for Inspecting the Wall Thickness of Offshore Risers from the Inside.- Transducer Array for Ultrasound Holographic B-Scan Imaging.- Image and Signal Processing.- Accurate Reconstruction of Flaws in Materials Using a Synthetic Aperture Ultrasonic Imaging System.- Parametric Approach on Field Propagation.- Performance of Fast Inverse Scattering Solutions for the Exact Helmholtz Equation Using Multiple Frequencies and Limited Views.- An ECG-Gated Colour Doppler Imaging System for Determination of Coronary Bypass Graft Patency.- A Two-Dimensional PVDF Transducer Matrix as a Receiver in an Ultrasonic Transmission Camera.- A New Digital Scan Processor for Ultrasonic Imaging.- Direct Imaging.- A Real-Time Imaging System for Non-Destructive Evaluation.- Implementation of a Real-Time Ultrasonic SAFT System for Inspection of Nuclear Reactor Components.- Flaw Identification in ALOK Imaging System.- A New Surface Acoustic Wave Imaging Technique.- Acoustical Imaging Techniques - Theoretical and Experimental Results.- A Flow Imaging and CW Spectral Analysis System.- Multidimensional Ultrasonic Heart Imaging.- Tomography.- Optimal Incident Angles in Scanning Tomographic Microscopy.- Ultrasonic Reflection Tomography with a Transmitter - Receiver System.- Speckle in Ultrasound Computerized Reflection Mode Tomography.- Analysis of Inverse Scattering Solutions from Single Frequency, Combined Transmission and Reflection Data for the Helmoholtz and Riccati Exact Wave Equations.- Attempt to Include Refraction in an Ultrasonic Tomography Algorithm.- Acoustical Microscopy.- Back-Projection Algorithms for a Computer-Controlled Scaning Laser Acoustic Microscope.- Directional Acoustic Microscope with Electrical Reference Signals.- Focal Plane Detection in Acoustical Imaging.- Progress Toward a Practical 100 MHz Scanning Laser Tomographic Acoustic Microscope.- Thermoacoustic Imaging Using a Laser Probe.- A High Performance Acoustic Microscope - Technical Aspects and Selected Applications.- Subsurface Imaging in Acoustic Microscopy.- Poster Session.- Relation Between Spatial Frequency Sampling Window and Lateral Resolution in Backward Propagation Acoustical Imaging.- Applications of Digital Image Enhancement Techniques to the Ultrasonic NDE of Composite Materials.- Some Problems and Experimental Results of Seismic Shallow Prospecting.- A Modified Sum Focussing Approach to Ultrasonic Speckle Reduction.- Dereverberation Techniques.- Polarity-Sensitive Detection of Pulsed Ultrasound Signals.- Ultrasonic Defects Visualization in a Metal Block.- Generalized Holography as an Improved Version of Conventional Acoustical Holography.- Joint Fourier Transform Cross-Correlation for Liver Echotexture Classification.- A Two-Element Annular Array of Short Fixed Focal Length for Dynamic Focussing.- Acoustic Imaging of Solid Objects in Air Using a Small Set of Transducers: III Experimental Demonstration.- Other Imaging Techniques.- A Broadband - Holography Imaging System for Nondestructive Evaluation.- Efficient Acoustical Holography and Phase Imaging with High Resolution at 3.6 MHz Using a Liquid Crystal Converter.- NDE in Multilayers: Theory, Computer Simulation and Experiments.- Underwater Acoustic Imaging.- Synthetic Aperture Sonar for Sub-Bottom Imaging.- Vertical Seismic Profiling Depth Migration of A Salt Dome Flank - A Summary.- A Sensor-Efficient Algorithm for Array Processing.- Acoustical Imaging and Point Processes.- High-Resolution Acoustical Image Reconstruction Algorithm for Finite-Size Objects: The Cascade Form.- Underwater Acoustical Holographic Imaging by a Square Array System.- Imaging the Nearfield of a Submerged Plate Using Acoustical Holography.- Participants.- Author index.