Abstract: A multi-spectral decentered catadioptric-type optical system suitable for use with long range oblique aerial reconnaissance camera systems, spectrum analyzers, astronomical imagers, remote sensing, and other applications is described. The optical system includes an aspheric primary mirror receiving incident radiation and defining a central aperture. An aspheric secondary mirror is provided for receiving the radiation from the primary mirror. The primary and secondary mirrors are positioned and constructed such that entrance aperture of the system is displaced or decentered relative to the optical axis of the system, so as to thereby increase the modulation transfer function of the optical system as compared to a centrally obscured system.The aspheric secondary mirror directs the incident radiation onto a means for splitting the radiation to a first optical path and a second optical path.

Abstract: An electro-optical step-frame camera system in which successive overlapping frames of scene imagery are generated by an electro-optical imaging array, and in which electronic image motion compensation is performed by the array during the generation of at least some of the frames of imagery. The successive frames of imagery are made in a stepping pattern that is repeated in a series of cycles of steps, each step separated by a framing interval in which a frame of imagery is obtained. The stepping cycles of the camera generate sweeping coverage of the terrain of interest. As the velocity to height ratio of the reconnaissance aircraft changes, the stepping cycle and electronic image motion compensation are continually adjusted, so as to ensure maximum scene coverage and preservation of image resolution.

Abstract: An optical device for a micro-image viewer or a micro-image viewer-printer machine receives a projected image of an illuminated micro-image, adjusts the spatial disposition of the projected image in an image plane and transmits the adjusted projected image to a viewing screen for viewing or to an exposure station for reproduction purposes. The optical device, in a preferred embodiment, includes a pechan prism positioned in a micro-image viewer-printer machine for receiving a projected image from a projection lens assembly. The pechan prism is rotatable about the illumination path or optical axis of the viewer-printer machine to enable the spatial disposition of the projected image to be rotated at least from 0 degrees to 180 degrees in an image plane.

Abstract: An optical device for a micro-image viewer or a micro-image viewer-printer machine receives a projected image of an illuminated micro-image, adjusts the spatial disposition of the projected image in an image plane and transmits the adjusted projected image to a viewing screen for viewing or to an exposure station for reproduction purposes. The optical device, in a preferred embodiment, includes a pechan prism positioned in a micro-image viewer-printer machine for receiving a projected image from a projection lens assembly. The pechan prism is rotatable about the illumination path or optical axis of the viewer-printer machine to enable the spatial disposition of the projected image to be rotated at least from 0.degree. to 180.degree. in an image plane.