Acoustical holography

Abstract

The purpose of this book is to present the basic principles of acoustical holography and its application to underwater acoustic waves. The text attempts to cover of is involved with special reference to the electronic reference technique. What I intend to do here is to describe how acoustical holography works, its development since its inception a few years ago and some of the current experimental methods and the problems that must overcome before the technique can become a useful tool in practice. Chapter 1 covers the introduction to and fundamentals of acoustical holography. Brief description is given on several methods employed for the detection of ultrasound fields in mediums with the relative properties they possess. Chapter 2 deals with the electronic recording and processing of ultrasound information as picture information. Detailed circuits are given for the master generator, the gating arrangement the amplification stages, the detector, and the paper marker-circuit arrangement. The majority of these circuits were constructed and tested, with the exception of the high frequency amplifier stage as the required electronic components were unavailable. A practical scanning array is described in the last chapter together with resolution considerations of the holographic technique.