I-tek, Inc.

United States of America As Represented by the Secretary of the Air Force

Litton Systems, Inc.

John T Watson

Bruce A Horwitz

Allen H Greenleaf

Kenneth D Stumpf

Robert F Lucy

A method and apparatus for phasing the apertures of a multiple-aperture imaging system is disclosed. An imaging system gathers light in either a scanning or a staring mode from a natural or real scene without artificial light sources. The spatial frequency of the image is sensed. The phase of the apertures is adjusted until the spectral power is maximized within a preselected spatial frequency band. When the spectral power is maximized, the apertures are optimally phased.

Real scene imaging system pupil phasing method and apparatus

A wavefront sensor apparatus for a large optical system, such as a telescope, having a reticle with at least one slit therein to provide image signatures for various portions of the aperture to an array of infrared sensor cells. The time differences between the image signatures represents relative image displacement caused by the wavefront slope variation in the actual wavefront.

Universal wavefront sensor apparatus

A measuring arrangement is disclosed for measuring the contour of a two or three dimensional surface in which a redundant configuration of distance measuring systems is positioned above the surface being measured. Each distance measuring system monitors distance measurements to a point proximate the surface as the measuring point is moved across the surface. The distance measurements are taken from a sufficient number of points on the surface such that a sufficient quantity of data is obtained to define the system geometry and also to define the position of each measurement point. The data is transformed by recognized mathematical techniques into the coordinate positions of all of the measured points on the surface. In one embodiment for measuring the contour of a three dimensional surface, a tetrahedral arrangement of four distance measuring interferometers includes three interferometers positioned in a planar array above the measured surface and a fourth interferometer positioned at a central apex thereof. A retroreflector is placed adjacent to the measured surface to define the measuring point, and is selectively movable across the measured surface. A tetrahedral truss is positioned above the measured surface, and each interferometer has a beam steering head at one corner of the truss to aim the interferometer beam at the retroreflector during movements thereof. Each interferometer further includes a servo control system for controlling the beam steering head to maintain the interferometer beam aimed at the retroreflector.

Self calibrating contour measuring system using fringe counting

An improved system for detecting movement of an image formed by a reconnaissance optical system. A photodiode array is placed in the focal plane of the optical system to detect the image. The photodiode array is first read out at a time T into a shift register where the signal is stored. After passage of a time .DELTA.T the photodiode array is read out a second time. The first and second read out signals are then correlated to determine the amount of movement of the image between times T and T + .DELTA.T.

Growing community of inventors

Lexington, MA, United States of America

John T Watson