Abstract: A process for reducing background clutter of a scene, and isolating an object of interest. The process includes calculating a minimum output from a plurality of appropriately configured anti-median filters representing a minimum difference processor (MDP) filter. In a first embodiment, the MDP filter includes a (5.times.5) matrix of elements wherein each element has an intensity value representation of the scene. A first anti-median filter array is configured as a horizontal array of 5 pixel elements in which the center element of the matrix is the center element of the horizontal array. A median value of the 5 elements of the horizontal array is determined, and is subtracted from the value of the center element to determine an anti-median value of the horizontal array. The same process is performed for a vertical 5 element anti-median array, and two diagonal 5 element anti-median arrays, all including the center element of the matrix as the center common element of the arrays.

Abstract: A sensor system includes a sensor (20) having an array (22) of detector elements (24), a movable sensor positioner (32) in which the sensor (20) is mounted, a signal processor (30) that progressively corrects the intensities of the pixels of a sensor output array for detector element nonuniformity, an electronic scene position corrector (40), and a motion controller (36) that provides a movement command (34) to the sensor positioner (32), and transmits the substance of the movement command to the scene position corrector (40). An image array signal is furnished from the sensor (20) to the signal processor (30), while the sensor positioner (32) is controllably moved under command of the motion controller (36). A nonuniformity-compensated output signal (38) of the signal processor (30) is provided to the scene position corrector (40), wherein the position of the image is corrected for the motion of the sensor positioner (32).

Abstract: An image discriminator which automatically enhances the ability of a system to discriminate between sources that can not be removed by fixed spectral cancellation. The invention (10) includes a mechanism (12, 14, 16, and 18) for separating input energy into first and second frequency bands and providing first and second signalscorresponding thereto. The ratio of the amplitudes of the first and second signals are varied by variable gain amplifiers (20 and 22) and subtracted from each other by a subtractor 24 to provide a control signal. The control signal is used in a tracker circuit 24 to control the gain of the first and second signals. Third and fourth signals are extracted by dual on-track signal rejection (28 and 30) from the first and second signals which represent energy from non-tracked objects. Circuitry (34 and 36) is provided for varying the ratio of the amplitudes of the third signal and the fourth signal in at least two trials.

Abstract: A self-stabilizing optical scanner system comprising a multi-faceted mirror includes a plurality of large and small facets formed on or attached to a gyro rotor, which rotor is adapted for being gimbal mounted, such that as each facet is rotated through the optical path of an energy receiving lens system, a detector is optically scanned across a field of view along a first dimension. In one embodiment, each mirror facet is inclined at a different angle to the rotor spin axis such that as the rotor revolves a two-dimensional pattern is scanned; and in a second embodiment a driven mirror is disposed in the optical path of the received energy so as to provide scanning along the second dimension.

Abstract: The antinarcissus reflector assembly comprises: a cold stop subassembly that includes an aperture; and a concave spherical mirror having an opening, and also having a center of curvature at the center of the aperture of the cold stop subassembly. Unlike in the prior art devices, the only cold surface that is seen by the optics ahead of the detector is the face portion thereof, which shows through the opening in the concave spherical mirror, rather than reflections of the interior of the cold stop subassembly. Therefore, the undesirable diffused, cool patch which appears in the center of the picture when prior art devices are used is eliminated or, at the very least, is minimized.

Abstract: A self-stabilizing optical scanner system comprising a multi-faceted mirror formed on or attached to a gyro rotor, which is adapted for being gimbal mounted, such that as each facet is rotated through the optical path of an energy receiving lens system, a detector is optically scanned across a field of view along a first dimension. In accordance with one embodiment, each mirror facet is inclined at a different angle to the rotor spin axis such that as the rotor revolves a two-dimensional pattern is scanned; and in accordance with a second embodiment a driven mirror is disposed in the optical path of the received energy so as to provide scanning along the second dimension.