Recon/optical, Inc.

Andre G Lareau

Stephen R Beran

Russell A Bennett

Brian O James

William R Pfister

John A Lund

George Hines

Michael Bown

Steven R Beran

James P Quinn

Barry E Swartz

Gilbert W Willey

Robert J Lintell

Bradford Speer

James P Karins

Christopher P Warren

Kenneth J Jerkatis

Gordon L Bourns

A two-dimensional focal plane array (FPA) is divided into sub-arrays of rows and columns of pixels, each sub-array being responsive to light energy from a target object which has been separated by a spectral filter or other spectrum dividing element into a predetermined number of spectral bands. There is preferably one sub-array on the FPA for each predetermined spectral band. Each sub-array has its own read out channel to allow parallel and simultaneous readout of all sub-arrays of the array. The scene is scanned onto the array for simultaneous imaging of the terrain in many spectral bands. Time Delay and Integrate (TDI) techniques are used as a clocking mechanism within the sub-arrays to increase the signal to noise ratio (SNR) of the detected image. Additionally, the TDI length (i.e., number of rows of integration during the exposure) within each sub-array is adjustable to optimize and normalize the response of the photosensitive substrate to each spectral band. The array provides for parallel and simultaneous readout of each sub-array to increase the collection rate of the spectral imagery. All of these features serve to provide a substantial improvement in the area coverage of a hyperspectral imaging system while at the same time increasing the SNR of the detected spectral image.

Multispectral or hyperspectral imaging system and method for tactical reconnaissance

An aerial reconnaissance system generates imagery of a scene that meets resolution or field of view objectives automatically and autonomously. In one embodiment, a passive method of automatically calculating range to the target from a sequence of airborne reconnaissance camera images is used. Range information is use for controlling the adjustment of a zoom lens to yield frame-to-frame target imagery that has a desired, e.g., constant, ground resolution or field of view at the center of the image despite rapid and significant aircraft altitude and attitude changes. Image to image digital correlation is used to determine the displacement of the target at the focal plane. Camera frame rate and aircraft INS/GPS information is used to accurately determine the frame to frame distance (baseline). The calculated range to target is then used to drive a zoom lens servo mechanism to the proper focal length to yield the desired resolution or field of view for the next image. The method may be performed based on parameters other than range, such as aircraft height and stand off distance.

Autonomous electro-optical framing camera system with constant ground

A camera system is described which is based on an electro-optical imaging array performs electronic image motion compensation without moving parts during a reconnaissance maneuver in which the aircraft is experiencing a non-zero rate of change in the pitch axis, such as in a dive bomb maneuver when the pilot is pulling out of the dive. The camera system has a camera control computer that calculates a pixel information transfer rate for the array based on parameters supplied by the aircraft's navigation system and pre-mission known parameters, including the aircraft's velocity, height above ground, attach angle, pitch angle, and rate of change in pitch during the period in which the array is taking successive exposures of the scene. The camera control computer supplies information to the drive and control electronics that control the transfer of pixel information in the array. In a preferred embodiment, the array is exposed to the scene of interest in a series of rapid exposure intervals and generates a frame of imagery during each exposure. By virtue of the electronic image motion compensation, each frame of imagery is a high resolution image of the scene of interest, far surpassing images created by an electro-optical array if the present image motion compensation technique were not performed.

Electro-optical imaging array and camera system with pitch rate image

An electro-optical imaging array having pixels arranged in rows and columns electronically compensates for image motion in the plane of the array regardless of whether the motion vector is in the row direction, the column direction, or in a diagonal direction, i.e., in some vector combination of row and column directions. In an aerial reconnaissance application, the image motion may be due to rotation of the aircraft about roll, pitch and/or yaw angles in addition to forward velocity of the aircraft. The image motion compensation is achieved with no moving parts and does not require a stabilized platform. A camera control computer determines the magnitude and direction of the image motion from inertial navigation system inputs, including velocity, flight, and aircraft rotation information, and calculates pixel information transfer rates in the row and column directions. The pixel information transfer rates are supplied to a counter and clock driver circuit for the array. The pixel information in the array is transferred in the row and column direction in a step-wise fashion in the row and column directions at a rate and direction substantially matching the image motion. The array itself is provided with a gate and control line design to enable charge representing pixel information to be transferred in both the row and column directions.

Electro-optical imaging detector array for a moving vehicle which

An electro-optical imaging array provides compensation for image motion due to variations in scene terrain electronically and with no moving parts. Pixel information representing scene information is transferred through the array in column groups. Each column group has its own charge transfer rate U. Successive images of the scene are generated by the imaging array, and the images are correlated by electronic signal processing circuitry to determine the image displacement of a fixed point in the scene between successive images. The image displacement is used to calculate a residual image velocity U.sub..delta. in each column group. As successive images of the scene are generated, the charge transfer rates U for each column group are updated, whereby U=U.sub.0 -U.sub..delta., where U.sub.0 is the charge transfer rate for the previous exposure, and U.sub..delta. is the residual image velocity in each column group.

Electro-optical imaging array with profiled foward motion compensation

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.

Method and camera system for step frame reconnaissance with motion

An electro-optical area array reconnaissance detector is disclosed which accomplishes forward motion compensation electronically and without moving parts. The array is made of photo-sensitive cells arranged in rows and columns, the columns being organized into one or more column groups. Charge packets collected in the cells representing scene information are transferred down the columns at the same rate as the image motion in the plane of the array. In a side oblique reconnaissance scenario, the columns may be organized into 16 column groups, each column group having its own charge transfer rate corresponding to the image motion rate in that column group.

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Bloomingdale, IL, United States of America

Andre G Lareau