A holographic system that records front-surface detail of a scene moving at high velocity

Abstract

It is known that any motion of the scene during the exposure of a hologram results in a spatial modulation of the recorded fringe contrast. On reconstruction this produces a spatial amplitude modulation of the reconstructed wavefront that tends to blur out the image. This paper discusses a novel holographic technique that uses an elliptical orientation for the holographic arrangement. It is shown that the degree of image degradation is not only a function of exposure time but also of the system used. The form of the functional system dependence is given, as well as the results of several systems tested, which verify this dependence. It is further demonstrated that the velocity of the target or the exposure time alone is inconsequential by itself and the important parameter is the total motion of the target Î X = VT. Using the resolution of front-surface detail from a target with a velocity of 17,546 cm/sec, we are able to predict an upper limit on target velocity for resolution of front-surface detail for a given system.