Investigation Of Passive Ranging Based On Infrared Image Sequence

Passive ranging becomes more and more important in the industry and military applications. It synthetical makes use of the techniques of the optics, sense of vision and picture. In the fields, such as the robot visual system, space satellite tracking system based on the analytical motion, the missile guidance system, the fly of automatic pilot machine, the accurate navigation system, the automatic analysis system of photographs of the military satellite, passive ranging all can be applicated. Passive ranging based on image processing is very promising in thiese fields.A passive ranging method based on the model of perspective projection is proposed in this thesis, according to the restrictions of lab. Expounding the model of perspective projection of IR probe system, tracking the stable feature points was presented. And then the length of feature component was acquired by the image processing. Analyzing the model of perspective projection for image seeker, the missile-target distance was attained during the tracking. Finally, an adaptive correction method was presented to increase the precision.In accordance with the characteristic analysis of airborne targets in IR image, local threshold segmentation based on the maximum distance method was used to segment the target image from background. Three conclusions of characteristic analysis of the local gray level were presented. The problems of fragments and furcations were solved by boundary tracking based on genetic algorithm.Feature extraction is a much more difficult work in the pattern recognition but it is also a main point of the automatic tracking system. Analyzing the typical IR images of airborne targets, the nose-cone of aircraft was selected as the stable feature component during the tracking, and the criterias of selection of the feature points were help to improve the measure precision.The method in this thesis meets the requirement of passive ranging based on the airborne targets in IR image sequence, which can be concluded from the result.