Study Of Imaging System Of Microbolometer Focal Plane Arrays

Infrared technique is a hotspot of current night-vision technology. Relying on its virtues such as small volume and weight, high reliability and performance-cost ratio, uncooled infrared imaging system plays an increasingly important role in the fields of watching and searching targets. On the basis of studying principles of infrared imaging system and real-time signal processing techniques of infrared focal plane arrays (IRFPA), this paper develops an uncooled infrared imaging system which integrates many functions such as the real-time signal processing, serial communication, keyboard service and TEC temperature controlling. The evaluation results indicate that this infrared imaging system satisfies military requirements.Studying the fundamental principles of uncooled infrared imaging systems is the basis of developing infrared imaging systems. This paper analyzes infrared imaging principles, factors affecting imaging systems' performance and working course of microbolometer IRFPA, discusses how to obtain the best performance of infrared focal plane arrays, and provides theoretical guide for the uncooled infrared imaging systems' design.The real-time ability of signal processing is a basic requirement for the imaging system. Nonuniformity correction, blank pixels' replacement and image enhancement is the main contents of signal processing. On the basis of a nonuniformity correction algorithm based on calibrating techniques, this paper develops a synthetic correction method based on two-point correction techniques and motion compensation techniques, a nonuniformity correction algorithm based on LMS filter and a nonuniformity correction algorithm based on time-domain statistics, which provides the signal processing module with multiple options. The nonuniformity correction algorithm based on time-domain statistics explains the IRFPA's nonuniformity with probability density function, and proves the equivalence between IRFPA's response' probability density function and its time-domain histogram. This property may be used to store image data, which solves the problem that the image data need amount of memory if we directly store them.Blank pixels' test is the precondition of realizing replacement. Referring to several checking methods and relying on the experiment analysis, this paper builds a blank pixels' judgement rule for microbolometer infrared focal plane arrays and obtains accordant effects with ULIS' method. To overcome the shortcomings of traditional structure of blank pixels' replacement, a replacement method based on the flag bit has been proposed. According to infrared images' characteristics, an adaptive image enhancement method...