A study of fast mechanical scanning for acoustical holography

Acoustical holography provides a technique with many current and potential uses. However, a convenient area detector equivalent to the photographic plate is not available for acoustical waves; this has initiated much research and a wide variety of recording techniques have been developed. Most of these methods, however, suffer either from lack of sensitivity, or a prohibitively small recording area. One way to combine good sensitivity without potential aperture limitation, is to scan the area with a sensitive receiver. Scanning techniques offer great versatility, such as range gating, source scanning, electronic reference simulation, imaging of large or thick objects, signal processing and insonification by reflection. Such a method, however, introduces an undesired scanning time which is troublesome in most applications. [Continues].