Stereo line scanner
First Claim
1. A stereo line scanner for optical radiation reception and recording to enable provision of stereoscopic picture-like representation of remote objects from a moving instrument carrier, comprising in combination:
- a rotary plane mirror provided with means for causing it to revolve about an axis at an angle of substantially 45°
to its mirror plane,a second plane mirror in the vicinity of the periphery of said rotary mirror and having an elongated mirror surface of which the long dimension is oriented at right angles to the axis of revolution of said rotary mirror and of which the short dimension is oriented at an angle between 0° and
45°
to said axis of said rotary mirror,a radiation detector located on said axis of said rotary mirror for registering radiation received by the scanner and directed toward said detector by reflection from said rotary mirror, andan optical system for collecting radiation reflected from said rotary mirror in a direction parallel to said axis of rotation thereof so as to provide said collected radiation to said detector,the inclination of said second plane mirror to said axis of rotation of said rotary mirror and also the inclination of said axis to the direction of movement of said instrument carrier being such, that during one portion of a revolution of said rotary mirror, radiation is receivable from objects disposed on the opposite side of said axis from said second mirror in a beam of primary rays reflected directly by said rotary mirror toward said optical collecting system and during another portion of said revolution of said rotary mirror, radiation is receivable from objects so disposed in a beam of secondary rays reflected first by said second plane mirror and then again by said rotary mirror to proceed toward said optical collecting system and said detector, whereby a line scan of said secondary rays can be correlated with a line scan of said primary rays from the same objects, but taking place after an interval determined by the movement of said carrier past said objects, to provide stereoscopic data regarding the aspect and disposition of said objects.
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Accused Products
Abstract
A 45° rotary mirror illuminates a detector through an optical colling system and while facing downwards picks up a direct or primary line scan of objects located below in the plane of scanning. While facing upwards, the rotary mirror picks up a secondary line scan indirectly from below by reflection from a non-revolving plane mirror at an acute angle to the axis of rotation of the rotary mirror, which angle corresponds to the base angle of stereo scanning when the primary line scans are correlated with corresponding secondary line scans that respectively precede them by an interval corresponding to the travel time of the movable craft upon which the line scanner is carried along a base line distance determined by the inclination of the non-revolving plane mirror. That inclination is adjustable about a hinge axis perpendicular to the direction of travel of the carrying aircraft or spacecraft. The average angle of sight of scanned objects is adjustable in elevation and also, for drift compensation purposes, in azimuth. The laser of the heightfinding system can be incorporated into the scanner, directing its light to another 45° mirror rotating back to back with the first, so that back-scattered laser light will be picked up by the scanner'"'"'s detector to make possible calibration of the stereoscopic parameters, as well as showing the ground track on stereoscopic pictures produced by processing the detector output.
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Citations
7 Claims
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1. A stereo line scanner for optical radiation reception and recording to enable provision of stereoscopic picture-like representation of remote objects from a moving instrument carrier, comprising in combination:
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a rotary plane mirror provided with means for causing it to revolve about an axis at an angle of substantially 45°
to its mirror plane,a second plane mirror in the vicinity of the periphery of said rotary mirror and having an elongated mirror surface of which the long dimension is oriented at right angles to the axis of revolution of said rotary mirror and of which the short dimension is oriented at an angle between 0° and
45°
to said axis of said rotary mirror,a radiation detector located on said axis of said rotary mirror for registering radiation received by the scanner and directed toward said detector by reflection from said rotary mirror, and an optical system for collecting radiation reflected from said rotary mirror in a direction parallel to said axis of rotation thereof so as to provide said collected radiation to said detector, the inclination of said second plane mirror to said axis of rotation of said rotary mirror and also the inclination of said axis to the direction of movement of said instrument carrier being such, that during one portion of a revolution of said rotary mirror, radiation is receivable from objects disposed on the opposite side of said axis from said second mirror in a beam of primary rays reflected directly by said rotary mirror toward said optical collecting system and during another portion of said revolution of said rotary mirror, radiation is receivable from objects so disposed in a beam of secondary rays reflected first by said second plane mirror and then again by said rotary mirror to proceed toward said optical collecting system and said detector, whereby a line scan of said secondary rays can be correlated with a line scan of said primary rays from the same objects, but taking place after an interval determined by the movement of said carrier past said objects, to provide stereoscopic data regarding the aspect and disposition of said objects. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification