• Korean Journal of Optics and Photonics
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• v.32 no.4
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• pp.153-162
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• 2021

In this article, the design of a variable F-number and triple magnification infrared optical system is described. That is a two-in-one optical system that combines an infrared search and track (IRST) system and an electro-optical tracking system (EOTS), where an afocal optical system is added to the IRST optical system designed already. The performance target is determined by analyzing system performance, and then the specification in the optical system design is calculated. This optical system contains a warm stop making it possible that one optics has two different F/# by cutting the size of aperture, and that is designed to suit this optics. The system satisfies the requirement such as a modulation transfer function (MTF). For operational assessment, the movement of the focusing lens group is analyzed over the change of temperature and target distance. By using this optical system, it is possible to develop equipment having two functions, infrared searching and electro-optical tracking.

• Journal of Korea Multimedia Society
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• v.16 no.6
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• pp.746-755
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• 2013

This paper presents a three dimensional bilateral filter detecting target trajectory, extracting spatial target information using two dimensional bilateral filter and temporal target information using one dimensional bilateral filter. In order to discriminate edge pixel with flat background and target region spatially and temporally, spatial and temporal variance are used for an image and temporal profile. With this procedure, background and background profile are predicted without original target through two dimensional and one dimensional bilateral filter. Finally, using spatially predicted background and temporally predicted background profile, small target can be detected. For comparison of existing target detection methods and the proposed method, the receiver operating characteristics (ROC) is used in experimental results. Experimental results show that the proposed method has superior target detection rate and lower false alarm rate.