Detection of Early Fatty Plaque Using Quantitative Ultrasound Methods.- Pattern Recognition on Human Skin Tissue.- Quantitative Imaging of Acoustical and Histological Properties of Excised Tissues.- A Fast Algorithm for Transkull Brain Imaging.- Detection of Root Caries.- Reflex Transmission Imaging: Visualization and Evaluation of Calculi for Lithotripsy.- Self Focusing with "Time Reversal" Acoustic Mirrors.- Acoustic Phase Conjugation using Nonlinear Electroacoustic Interaction and Its Application to Scanning Acoustic Imaging Systems.- An Echolocation and Imaging Using Transducers of Directionally Distinguishable Impulse Response.- An Ultrasonic Robot Eye Using Neural Networks.- Inverse Scattering and Diffraction Tomography Using Intensity Data.- Reconstruction of Two-Dimensional Refractive Index Distribution Using the Born Iterative and Distorted Born Iterative Methods.- Decision-Theoretic Treatment of Superresolution Based Upon Oversampling and Finite Support.- A Generalized Framework for Incoherent Pulse Echo Processing and Imaging: The Random Phase Transducer Approach.- Spatial Pulse Response Computing for Reflection - Time Domain Approach.- NDE of Delaminations During Processing of Carbon-Carbon Composites.- Ultrasonic Imaging and Finite Element Analysis of Adhesively Bonded Cylinders.- Applications of High Resolution Deconvolution Techniques to Ultrasonic NDE.- Characterization of Layered Structures by a Liquid Wedge Transducer and a Corner Reflector.- Non-Destructive Evaluation of Engineering Ceramics by High-Frequency Acoustic Techniques.- Acoustic Microscopy of Ceramic Bearing Balls.- Evaluation of Skin Biopsy Samples Using Acoustical Microscopy and Comparison with Conventional Pathological Studies and Light Microscopy.- Observation of Stable Crack Growth in AL2O3 - Ceramics by Acoustic Microscopy and Acoustic Emission.- Direct Measurements of the SAW Velocity and Attenuation Using Continuous Wave Reflection Scanning Acoustic Microscope (SAMCRUW).- Electronic Scanning in Acoustic Microscopy Using a Wedge Transducer.- Holographic Scanning Laser Acoustic Microscopy and Applications.- Acoustic Images Observed by Directional PFB Microscope.- Initial Phase Estimation and Tomographic Reconstruction for Multiple-Frequency Acoustic Microscopy.- Deconvolution of Exploration Seismic Data.- Tomographic Reconstruction for Imaging EOR Processes in Hydrocarbon Reservoirs.- Geophysical Diffraction Tomography.- Imaging of the Nonlinear Acoustic Parameter B/A.- Least Squares Estimation and Imaging Using Phase and Frequency Measurements of the Nonlinear Parameter B/A.- Ultrasonic Time-of-Flight Tomography for the Non-Intrusive Measurement of Flow Velocity Fields.- Comparison of Estimation Strategies for the Determination of Blood Velocity Using Ultrasound.- Application of a New Aliasing-Defeating Method to Pulsed-Doppler Flow Imaging Systems.- Estimation of Center Frequency and Variance of Ultrasonic Doppler Signal by Using Second-Order Autoregressive Model.- An Optimization Method for Acoustic Impedance Estimation of Layered Structures Using Prior Knowledge.- The Feasibility of Real-Time 3D-Acoustical Imaging.- A Comparison of Broadband Holographic and Tomographie Imaging Concepts.- An Experimental Study of Diffraction Tomography under the Born Approximation.- Initial Testing of a Clinical Ultrasound Mammograph.- Modified Fresnel Approximation and Acoustical Holography.- Improvements of the Multilayer Holo-Acoustic Tomography by Iterative and Algebraic Techniques.- Development of an Underwater Frontal Imaging Sonar, Concept of 3-D Imaging System.- Signal Processing in the 1988 Monterey Bay Acoustic Tomography Experiment.- Results from an Experimental Synthetic Aperture Sonar.- High Resolution Wigner Distribution for Sonar Applications.- An Imaging Operator for a High Speed Holographic Sonar which Uses an Incompletely Orthogonalized Wavefront.- Three-Dimensional Display Technique for Fish-Finder with Fan-Shaped Multiple Beams.- Tu...

How to produce images with sound has intrigued engineers and scientists for many years. Bats, whales and dolphins can easily get good mental images with acoustical energy, but humans have little natural ability for obtaining such images. The history of engineering and science, however, is an impressive demonstration that technological solutions can compensate, and then some, for deficiencies of nature in humans. Thus with the proper technology, we too can "see" with sound. Many methods involv ing ultrasonic energy can be employed to enable us to do so. Few of these methods are at all reminiscent of the acoustic systems employed by animals. Pulse-echo, phase-amplitude and amplitude-mapping approaches constitute the conceptual bases for three fundamentally different types of acoustic imaging systems and can be used for categorizing the systems. However, by now systems exist that combine the approaches in such sophisticated ways as to make an unambiguous categorization of some of the more complicated systems difficult or impossible. Among the instruments so far pro duced are mechanically-scanning focused instruments, chirped pulse-echo instruments, and instruments involving holography, tomography, parametric excitation, phase conju gation, neural networks, random phase transduction, finite element methods, Doppler frequency shifting, pseudo inversion, Bragg diffraction and reflection, and a host of other principles. The fifty-five chapters in this volume are selected from papers presented at the Eighteenth International Symposium on Acoustical Imaging which was held in Santa Barbara, California on September 18 - 20, 1989.

The latest progress in acoustical holography and related research areas, generally involving imaging by means of acoustic waves, was discussed and treated in depth at the Fourth International Symposium on Acoustical Holography, held in Santa Barbara, California on April 10-12, 1972. This volume contains the proceedings of that symposium. As the papers presented here indicate, a num ber of startling advances have been realized in the state-of-the-art since publication of Volume 3 of Acoustical Holography. Progress has been partic ularly impressive in the field of acoustical imag ing. The Fourth International Symposium represents something of alandmark conference in this respect. The scope of this volume is substantially broad er than the term "acoustical holography' usually implies and encompasses the whole area of visualiza tion, detection, and recording of sound fields whether with long wavelengths, microwaves, or with extrememly short sound wavelengths. The 37 sympo sium papers appear here each as aseparate chapter. In general, the work reported deals mainly with ex perimental and theoretical developments in the a bove areas. This work has significant practical potential use in terms of seismic sensing, under water imaging, non-destructive testing, real-time acoustic microscopy, and medical diagnosis."