Digital reconstructions from ultrasonic systems
Van Rooy, David Lee
Jordan, James A.
Master of Arts
Experiments using the computer to reconstruct images from ultrasonic wavefront data are described. Several methods for display of these images are also presented, including computer-generated visible wavelength holograms and kinoforms. These display methods show promise of providing a more convenient means of displaying images formed by ultrasound. Ultrasonic holography (Gabor type) has been performed and a digital reconstruction of a small aperture has been obtained. A new technique of recording the amplitude and phase of the diffracted ultrasonic wavefront yields only one image (no central order) upon reconstruction. The wavefront is merely back propagated within the computer to obtain the original image. More complex objects have been reconstructed using this method. Kinoforms and kinoform lenses, including an ultrasonic lens, are also discussed.