Recon/optical, Inc.

William R Pfister

Stephen R Beran

Andre G Lareau

Brian O James

Russell A Bennett

Barry E Swartz

John A Lund

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 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

Improved apparatus and methods of image information processing are disclosed which extend the operational coverage of an image system to higher velocity to height ratio scenarios while optimizing image resolution. The invention typically is implemented by a time delay and integrate charge-coupled device. In conjunction with an image variable row scan rate, a novel method of clocking the device is used to adjust the number of cycles of clocking performed in one row read out time, and to simultaneously transfer pixel information located in a plurality of rows of an imaging array having a predetermined row relationship. The relationship between the variable row scan rate, the predetermined row relationship and the number of cycles of clocking is adjusted so that the scan rate can increase above a maximum base scan rate by a factor of (AB)/(B-1), where A is the number of cycles of clocking performed and B is an integer corresponding to the predetermined row relationship. This increased scan rate and clocking optimizes resolution in the extended operational coverage scenario at (B-1)/(AB). In some non-scanning applications, the velocity to height ratio will determine the rate of image movement across the array, and the row relationship and the number of cycles of clocking will be the chosen parameters to optimize resolution.

Image information processing techniques for improving the resolution of

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.

Electro-optical imaging array with motion compensation

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Schaumburg, IL, United States of America

William R Pfister