Northrop Grumman Systems Corporation

Northrop Corporation

David D Garber

James J Reis

Anthony L Luk

Antonio B Lucero

Method and apparatus for guiding a projectile to a target in a scene using a scene imaging sensor in which the projectile has a guidance and control system for aiming the projectile. A first tracker analyzes the scene and selects a first track point representative of a target and a first confidence value serving as a reliability measure of the first selected track point. A second tracker analyzes the scene and selects a second track point representing the target and a second confidence value which serves as a reliability measure of the second selected track point. Each of said trackers are constructed and arranged to operate independently in a manner that is substantially statistically uncorrelated with respect to each other. A joint confidence value based on track point proximity, convergence and divergence is generated from the tracker data and a composite confidence index is calculated from the first and second confidence values and the joint confidence value. The first and second track points are linearly combined pursuant to one of a set of rules selected by the confidence index to provide a new track point which is outputted to the projectile guidance and control system and new start track points are generated that are specially suited to restart the trackers in a new operation cycle.

Hierarchical tracker and method

An automatic target acquisition and tracking system has been developed for a focal plane array seeker. The automatic target acquisition is achieved by three independent target acquisition algorithms, viz., the maximum likelihood classification, the video spatial clustering, and the target-to-interference ratio. Each algorithm operates asynchronously and provides independent target detection results. Target information is then combined hierarchically in a probabilistic fashion and prioritized. The highest priority target is handed off to a dual mode tracker consisting of a minimum absolute difference correlation tracker and a centroid tracker. The dual mode tracker subsequently provides a feedback signal to a proportional navigation system or other guidance/control system for directing the flight path of a munition.

Target acquisition and tracking system

A filter for decreasing sensor artifacts in an image frame as, for instance, sensor induced streaking in the image frame, has a frame buffer for temporary storing the picture elements of the image frame. A picture element mask is utilized to group related picture elements and statistics are collected with respect to these grouped picture elements. Correction parameters are determined utilizing these statistics and these are then utilized to correct the individual picture elements to remove the sensory induced artifacts. The statistics can be collected with respect to picture element gain and picture element offset with the correction parameters then determined utilizing the picture element gain and picture element offset.

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Cypress, CA, United States of America

David D Garber