Cassegrain optical system for framing aerial reconnaissance camera
First Claim
1. A dual band optical system for a framing aerial reconnaissance camera, said camera including at least two two-dimensional image recording media for generating frames of imagery of a scene external of an aerial reconnaissance vehicle carrying said camera, comprising;
- (a) a Cassegrain optical system forming an objective lens for said optical system, said Cassegrain optical system receiving incident radiation from said scene and comprising a primary mirror having a central aperture and a secondary mirror, said primary and secondary mirrors aligned along an objective optical axis;
(b) an azimuth mirror receiving radiation from said secondary mirror, said azimuth mirror placed between said secondary mirror and a Cassegrain image plane and directing radiation in a direction away from said objective optical axis; and
(c) a spectrum dividing element receiving radiation from said azimuth mirror, said element directing radiation in a first band of the electromagnetic spectrum into a first optical path and directing radiation in a second band of the electromagnetic spectrum into a second optical path different from said first optical path;
(d) wherein a first two-dimensional image recording medium is placed in said first optical path and a second two-dimensional image recording medium is placed in said second optical path, said first and second image recording media generating first and second images in two different portions of the electromagnetic spectrum simultaneously.
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Accused Products
Abstract
A dual band optical system for a framing aerial reconnaissance camera is described. The camera including at least two two-dimensional image recording media for generating frames of imagery of a scene external of an aerial reconnaissance vehicle carrying the camera. The camera includes a Cassegrain optical system forming an objective lens for the optical system, including a a primary mirror having a central aperture and a secondary mirror. The primary and secondary mirrors are aligned along an objective optical axis. The optical system also includes an azimuth mirror receiving radiation from the secondary mirror. The azimuth mirror is placed between the primary and secondary mirrors. A spectrum-dividing element in the form of a prism receives radiation from the azimuth mirror. The spectrum-dividing element directs radiation in a first band of the electromagnetic spectrum into a first optical path and radiation in a second band of the electromagnetic spectrum into a second optical path different from the first optical path. A first two-dimensional image recording medium is placed in the first optical path and a second two-dimensional image recording medium is placed in the second optical path. The first and second image recording media generating first and second images in two different portions of the electromagnetic spectrum simultaneously.
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Citations
19 Claims
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1. A dual band optical system for a framing aerial reconnaissance camera, said camera including at least two two-dimensional image recording media for generating frames of imagery of a scene external of an aerial reconnaissance vehicle carrying said camera, comprising;
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(a) a Cassegrain optical system forming an objective lens for said optical system, said Cassegrain optical system receiving incident radiation from said scene and comprising a primary mirror having a central aperture and a secondary mirror, said primary and secondary mirrors aligned along an objective optical axis;
(b) an azimuth mirror receiving radiation from said secondary mirror, said azimuth mirror placed between said secondary mirror and a Cassegrain image plane and directing radiation in a direction away from said objective optical axis; and
(c) a spectrum dividing element receiving radiation from said azimuth mirror, said element directing radiation in a first band of the electromagnetic spectrum into a first optical path and directing radiation in a second band of the electromagnetic spectrum into a second optical path different from said first optical path;
(d) wherein a first two-dimensional image recording medium is placed in said first optical path and a second two-dimensional image recording medium is placed in said second optical path, said first and second image recording media generating first and second images in two different portions of the electromagnetic spectrum simultaneously. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A Cassegrain optical system for a framing aerial reconnaissance camera, said camera including a rigid camera housing, comprising:
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a primary mirror receiving incident radiation from a scene external of said vehicle;
a secondary mirror receiving radiation from said primary mirror;
an azimuth mirror positioned between said primary mirror and said secondary mirror;
said primary and secondary mirrors defining an objective optical axis;
a primary mirror cell fixedly mounted to said camera housing;
a primary mirror holding ring receiving said primary mirror and movable with respect to said primary mirror cell;
structure rigidly coupling said secondary mirror to said primary mirror; and
a motor system coupled to said Cassegrain optical system adapted for rotating said primary mirror, secondary mirror and azimuth mirror about an axis orthogonal to said objective optical axis. - View Dependent Claims (16, 17, 18, 19)
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Specification