Patent ID: 6374047
Filing Date: 2002-04-16
Classification: G01C

Abstract:
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.