Research On Key Technology Of Infrared Search And Warning System Based On Surface Array Detector

With the escalation of warfare pattern, the infrared search and track system is becoming the necessary weapons of territorial airspace. Therefore, the topic presents a kind of searching method based on scanning array detector, which is used to do the searching task instead of traditional linear array detector, so the recognition of small target such as long-distance head-on aircraft and missiles will be accomplished.The system of array scanning has been carried out in this topic deeply. The operating distance formula is deduced by improving the signal-to-noise ratio and the advantage in the distance is validated by comparing and analysing. And in view of the characteristic of array scanning, the small target is presented like line target as the subsequent detecting object. According to the complexity and changeable characteristics of infrared background, we propose a thought of target detection on account for the background classification. The background is divided into two categories, on the top of feature line and under the feature line. Meanwhile the background on the top of feature line is also divided into two classes, within the cloud and outside the cloud. Subsequently different detection algorithms are used to deal with different backgrounds. Besides, we propose an enhanced match-filter detection algorithm. This algorithm can facilitate the high frequency information of the edge of the target by overlying the pixel of two boundary line so as to detect the target easily. We propose an algorithm based on coordinate statistics that can control the constant false-alarm rate. After the initial target detection being accomplished, it can adaptively divide the segmentation regions in accordance with the target coordinates and dynamically update the regional segmentation threshold, which could reduce the constant false alarm rate of the system and effectively lower the algorithm complexity. Besides, to achieve a good real-time performance, the system implementation architecture is based on FPGA+PC. Large amounts of outfield experiments have confirmed that our algorithm framework has a high accuracy of detection and better stable performance in long-distance infrared small target detection.