Abstract: An optical display system for a craft navigation simulator providing a wide angle display of greater than 3:1 width/height format derived from a closed circuit television camera viewing a terrain model. A wide-angle scene viewed is divided into three or more parts at vertical boundaries all of which are off-center and folded by a first optical system into substantially square format, in which format the composite image is processed from camera tube to display tube. A second optical system reconstructs the original wide angle image. By this means, high definition of the image in the center region and, particularly, near the horizon, is maintained.

Abstract: Head-coupled visual display apparatus for a sole observer, particularly in craft flight simulation apparatus, for providing to a pilot a view simulating that seen from an actual craft. The apparatus includes an image generator of known type, such as closed circuit television or computer generated image types, an image projector, a helmet with a binocular viewer attached and a movable optical path linking the image projector with the helmet viewer. The helmet binocular viewer comprises a beam-splitter, which splits the image beam into left-eye and right-eye beams, and left-eye and right-eye mirrors, which reflect the corresponding image beams onto a retro-reflective screen, and which permit the pilot to view the cockpit and the reflected image therethrough. Sensing means detect head movements of the pilot and the generated image is changed correspondingly, to permit voluntary scanning of a wide angle field of simulated view.

Abstract: An optical system for selectively modulating one or more colors of light in a polychromatic light beam. Using a laser source, all colors are initially plane polarized in a preferred direction. Any selected color is modulated using an electro-optic cell with an optical waveplate both before and following. The first waveplate rotates the direction of polarization of that selected color or another color to a direction at 45.degree. to the preferred direction. The electro-optic cell resolves incident light, solely of the selected color, into two right angle components polarized at .+-.45.degree. to the polarization of said another color. The relative amplitudes of the components is determined by an electrical signal applied to the cell. The second waveplate also rotates the direction of polarization of said selected color or said another color by 45.degree.. A final optical analyzer passes one component of all modulated colors while inhibiting the other component.

Abstract: A ground-based flight simulator having a television type terrain visual display with simulated weather conditions. The visibility of the terrain image is varied over the picture area to simulate ground fog and cloud conditions, either one alone or both together. Either weather condition provides a zone of transitional visibility, i.e., spatially changing visibility between spaced zones of uniform visibility, e.g., between one of uniformly clear visibility and another zone of uniformly zero visibility. The transitional zones may be varied in width according to aircraft pitch and the entire weather pattern rotated, together with simulated terrain, according to aircraft roll.

Abstract: A mirror drum type of light beam, or other radiation beam, scanning device comprising a rotating mirror drum and an arcuate set of optical, or like, elements arranged coaxially with the mirror drum. An incident beam, directed upon the mirror drum strikes each mirror face in turn as the drum rotates. Each mirror face sweeps the reflected beam across each optical element in turn of the arcuate set. Each optical element is adapted to return the beam to the same mirror face whence it came. The same beam is thereby deflected a second time by the same mirror face to produce an angular rate of rotation of the final reflected beam of four times the angular rate of rotation of the mirror drum.In a modification, a second mirror drum, with convex mirror faces, sweeps the beam over a concave mirror as a pre-scanner, so that the beam follows the reflecting mirror face of the main mirror drum, in rotation.

Abstract: An optical arrangement, particularly for ground-based flight simulating apparatus using an optical probe moving over a terrain model to provide a visual display of terrain overflown.The optical arrangement provides a fully in-focus image on a television camera tube target which is inclined relatively to the plane of the terrain model.The optical arrangement may equally be applied to a laser beam scanned terrain model.The arrangement comprises first and second optical systems, usually lenses or lens combinations, and a deflecting means therebetween, usually lens, prism and mirror elements, producing a tilt of the in-focus image plane of the overall system.

Abstract: A mirror drum type of light beam, or other radiation beam, scanning device comprising a rotating mirror drum and an arcuate set of optical, or like, elements arranged coaxially with the mirror drum. An incident beam, directed upon the mirror drum strikes each mirror face in turn as the drum rotates. Each mirror face sweeps the reflected beam across each optical element in turn of the arcuate set. Each optical element is adapted to return the beam to the same mirror face whence it came. The same beam is thereby deflected a second time by the same mirror face to produce an angular rate of rotation of the final reflected beam of four times the angular rate of rotation of the mirror drum.In a modification, a second mirror drum, with convex mirror faces, sweeps the beam over a concave mirror as a pre-scanner, so that the beam follows the reflecting mirror face of the main mirror drum, in rotation.

Abstract: An optical display system, particularly for providing the visual display of terrain overflown to the trainee crew of a flight simulator, and including an optical probe, closed-circuit television system and projection monitor providing a visual display scene upon a projection screen viewed by trainee crew, in which the displayed scene and the scene viewed by the probe are wide-angle and optical means are included to dissect the image into two parts, without image reduction on either axis, and to reassemble the image parts into a composite image of substantially square format, for transmission and reproduction by the television system, further optical means being used to rearrange the composite image parts to reproduce the original wide-angle scene.Image-splitting prism devices are used to provide the square format and to reproduce the wide-angle format.