Ground Type Inversion, Target Detection And Passive Ranging Based On Infrared Sequential Images

With the development of infrared sensor technology, staring infrared detection systems are being applicated more and more widely in the military field. Compared with the air and sea applications, it is more difficult in terrestrial applications. And the main problems are shown as follows: (1) the types of the target and the typical ground are complicated, (2) the target is easy to be blocked or submerged, (3) the system platform is relative locomotory commonly, (4) the imaging condition affects the detection performance, (5) the passive ranging is difficult, etc.According to the abovementioned difficulties, the inversion of the typical ground, the target detection under complicated ground condition and the passive ranging are investigated in this thesis. And the main contributions are shown as follows:1. The uniform single-level heat-exchange model is put forward, and the statistics characteristic for the typical ground infrared radiance is emulated, whose veracity is verified by the outfield infrared images. Then the thermal balance function is constructed, and the ground type is inversed by the hypothesis testing method based on the typical ground optic-electric parameters.2. The block matching method is improved to compensate the backgrouond motion quickly. Then, for the single-band IR detection system, the detection algorithm based on region of interest was put forward. Finally, for dual-band infrared detection system, a detection algorithm for ground weak small targets, which integrates the advantages in temporal-spatial domain, is propsed based on fusion of inter-frame difference images. Both of the algorithms can improve the detection capability.3. Aimed at the moving surface target, firstly, the round projection vector to compensate the background motion is improved. Then associated with the particle filter, the method combineing detection and tracking the ground moving surface target is proposed. In addition, according to uncertain size of the non-cooperative target, an algorithm is proposed based on the measurement of integrated information, which can not only guarante the detection effectiveness, but also be universal to both small and surface targets.4. The impact of imaging conditions on the gray scale of pixels is analyzed. In order to get the real apparent temperature of the background, the IR images are transformed based on the imaging condition. Then the feasure stes can be extracted from the pixel neighboring window, and the target was detected by hypothesis testing with the adaptive window chosen according to different imaging condition.5. The range model is founded based on the working principle of the staring IR imaging system. Considered the relationship between the pixel gray and the target's radiating power, the two ranging algorithms are derived based on one band and two band of the single station. Then the algorithms are validated by the outfield IR image, and the ranging error is analyzed.Finally, the composition, function, development and field experiment of the staring infrared detection system is summarized.