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The Naval Research Laboratory (NRL) has designed and fabricated a prototype seeker system with an Infrared Focal Plane Array (IRFPA) sensor and custom image processor. This prototype seeker system, developed and used as flyable IRFPA anti-ship cruise missile threat simulator to test ship based IR countermeasure systems has improved performance over existing anti-ship systems using scanning IR sensors and image processing hardware. This paper addresses the enhanced performance of the IRFPA sensor and the custom image processor system, both separately and in combination. A comparison of the specifications and performance of a modern IRFPA versus existing scanning sensor is performed to illustrate the benefits of staring arrays in IR guided systems. In addition to utilizing a compact IRFPA sensor, the prototype seeker system takes advantage of improvements in image processing hardware, general purpose CPUs, multiprocessing, multitasking operating systems. An automated nonuniformity correction (NUC) calibration algorithm for the IRFPA sensor will be described which allows in situ calibrations without external calibration sources or human operator intervention. The image processing hardware consists of three 68020 CPU cards running in parallel under the real-time operating system pSOS+m, a convolution card, a histogram card, and an image analysis card. The 68020 CPUs handle tasks controlling the image processing, target classification, tracking algorithms, and data collection. The seeker software accumulates a history of frame parameters, classifies potential targets, and commands the gimbal electronics to point the sensor. The tracking algorithm can maintain history and track of multiple targets. Field test results show that the added sensitivity and resolution of the IRFPA and increased processing capability of the seeker system provide increased maximum track range, more robust tracking, and countermeasure hardness.
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