Microwave Antenna Holography System
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Polarization effects in light scattering recorded by method using holographic interference patterns
Holographic optical computing image restoration method for a posteriori deblurring of photographs
Two holograms, made simultaneously, one with a red light component and one with the harmonic UV component to give two fringes in the UV construction due to shortened wavelength. The reconstruction, obtained with a He-Ne laser, could be photographed separately, giving quality interferograms.
Image deblurring and aperture synthesis using a posteriori processing by Fourier transform holographic spatial filtering
Acoustical holographic imaging techniques for noninvasive visualization of soft tissue structures in man
Holographic method for reconstructing polarization of light emitted by photoelastic model, obtaining isochromatic and isoclinic fringe patterns
Holographic method for reconstructing polarization of light emitted by photoelastic model, obtaining isochromatic and isoclinic fringe patterns
Holographic device for satellite attitude determination, providing three axis reference information in analog or digital form from single star field sampling
Time-average holographic interferometry applied to HF transverse vibrations of uniform cantilever beam, noting correlation with Timoshenko beam theory
Method photographs vibration modes as high as 100 kHz. Technique also measures vibration decay and damping characteristics. Compensation techniques for structural size limitations and for background noise excitations are discussed.
Supported rectangular plates HF transverse vibrations by holographic interferometry
Photographic emulsion model for signal to average noise irradiance ratio analysis in hologram reconstruction
A hologram has been made using a surface plasmon resonance wave as the reference beam. The surface wave was stimulated on a 1200-line/mm aluminum reflection grating that was coated with a thin layer of high-resolution photographic emulsion. Experimental results are presented.
Microwave holograms are made without offset reference beam, but it has been found that Van der Lugt filter can be used to produce image offset. Also, filter permits "decoding" of holograms in contrast with usual practice of reconstructing visible-light analogs of original micro-wave wave fronts.
Holographic methods permit use of very large effective apertures so that weak signals can be collected over wide area and integrated to form image. Technique, modification of side-looking radar principle, can be used at very short ranges needed for nondestructive inspection of test specimens.
Consideration of the problem of distortion posed by a long-wavelength hologram as a three-dimensional display to be viewed by an observer who is included in the distortion problem. The effects of holographic distortion upon the observer's image perception are examined. The inclusion of the visual perception process into the description of holographic imagery necessarily complicates the analysis, but at the same time increases the degrees of freedom by which the image can be altered. It is shown that these additional degrees of freedom make it possible to overcome the problem of unequal longitudinal and lateral magnification.
The speed of the holographic image deblurring method has recently been further enhanced by a new speed in the realization of the powerful holographic image-deblurring filter. The filter makes it possible to carry out the deblurring, in the optical computer used, in times of the order of one second. The experimental achievements using the holographic image-enhancement method are illustrated with examples ranging from out-of-focus or motion-blurred photographs, including 'amateur' photos recorded on Polaroid film, to the sharpening of the best available electron micrographs of viruses. Images recorded with X-rays, notably from rocket-borne photos of the sun, and out-of-focus photographs from cameras in NASA satellites have been similarly deblurred.