Loral Fairchild Corporation

Fairchild Weston Systems, Inc.

Ralph H Wight

James C McGlone

Gregory J Wolfe

A stabilized imaging system in which the lens assembly is fixed, and an electro-optic imager element is moveable to compensate for three-dimensional movements of the surrounding structure. Preferably the optical train also includes a movable prism, which can rotate the field of view in one plane. Rotation of the imager compensates for the image rotation caused by rotation of the prism.

Stabilized imaging system

The present invention is directed to a system and method for reducing image smear in an image which has been electronically collected by a TDI detector. In particular, the present invention is directed to an electronic imager having a charge accumulation device, such as a TDI detector. The charge accumulation device stores a row of electrical charges representing a sensed image. The charges are blurred due to motion of the electronic imager. The imager also includes a shift register for generating a blurred video line by concatenating the blurred charges. The blurred video line includes a series of pixel values proportional to the blurred charges. The imager also includes an image unsteadiness compensation for correcting the blurred video line. The image unsteadiness compensator generally operates as follows. First, the image unsteadiness compensator receives motion information from sensors, wherein the motion information describes the motion of the electronic imager. Then, the image unsteadiness compensator computes image wander of the blurred charges by using the motion information. Next, the image unsteadiness compensator generates a corrected video line from the blurred video line by using the image wander computation.

Electronic image unsteadiness compensation

Long range, non-linear, sector scan panoramic electro-optical reconnaissance of a scene from an airborne craft is performed at increased aircraft velocities with a given detector technology at a desired level of performance. A focal plane array is configured to detect an image of the scene, and to convert the image into electronic charge information representing the image. A main electronics unit that converts the electronic charge representation into an electronic signal which is a digital representation of the image. A lens arrangement is used to focus a narrow slit of the scene onto the focal plane array, and a rotating prism scans the slit across the scene at a non-linear scanning velocity as determined according to the present invention. The electronic signal is transmitted to a ground station where it is processed to provide visual image data and that represents the scene, distortion induced into this data as a result of the non-linear scan velocity is removed to provide a distortion free final image.

Nonlinear scanning to optimize sector scan electro-optic reconnaissance

A thermal or infrared imaging system having an optical barrel, an external stop formed by a mirror, a dewar, a cold shield, a focal plane array, and multiple retroreflectors. The cold shield and focal plane array are located inside the dewar. The mirror directs desired light bundles at the focal plane array. The retroreflectors are attached to the inside of the optical barrel. The retroreflectors are arranged such that the retroreflectors exist in all lines of sight of the focal plane array, except those lines of sight associated with the external stop. Consequently, the retroreflectors do not interfere with the desired light bundles which are focused onto the focal plane array. However, all light outside of that which is focused is prevented from reaching the focal plane array by the retroreflectors. The retroreflectors are infrared retroreflectors arranged in a matrix. Each of the retroreflectors is a 'concave' corner cube having low emissivity reflecting facets. The corner cubes reflect incoming rays by 180 degrees relative to input angles of the incoming rays. Thus, the focal plane array sees only cold outside of the desired light bundles.

Retroreflectors for increasing cold shield efficiency

An electro-optic system which is advantageous for low altitude, high speed aerial reconnaissance. A linear imager is movably positioned in the focal plane of a fixedly mounted wide-angle lens system. The fore-aft motion capability of the imager can be used to select an optimal viewing angle for recognition, for image motion compensation (to reduce smear), or for other functions.

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Northport, NY, United States of America

Ralph H Wight