Accession Number : ADD008156

Title :   Windscreen Angular Deviation Measurement Device.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Task,Harry L

Report Date : 10 Feb 1981

Pagination or Media Count : 6

Abstract : An apparatus for detecting the angular deviation from an axis imparted to a ray when passing through a transparent medium, for resolving the angular deviation into its components, and for generating electrical signals accurately representing the magnitudes of such components. A laser beam is projected along an optical axis through the medium and focussed by a displacement compensation lens. The beam is divided into channels with a beam splitter, each channel being incident upon a transmission diffraction grating. Each grating, characterized by fine parallel lines of substantially random size and spacing, generates a fan-shaped region of luminous energy. At a distance equal to the focal length of the lens, the fan-shaped regions cross detector arrays aligned parallel to the grating lines. A change in the angular deviation proportionally translates the crossing point along the detector array. (Author)

Descriptors :   *Patents, *Displacement, *Beams(Electromagnetic), *Goniometers, *Laser beams, Beam splitting, Optical properties, Gratings(Spectra), Sizes(Dimensions), Arrays, Compensation, Transmittance, Transparence, Crossings, Axes, Windshields, Demodulators, Luminosity, Angles, Energy, Lenses

Subject Categories : Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE