• Journal of Gifted/Talented Education
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• v.25 no.5
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• pp.697-709
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• 2015

This paper aims at shaping remote observatory system environment for schools, developing astronomical observation program using that system and applying it to science-gifted elementary students in order to figure out effects on their scientific investigation ability and attitude. in order to figure out effects of astronomical observation program using remote observatory program on scientific investigation ability and attitude of science-gifted elementary students, test was conducted on gifted students class of 5th grade in A Elementary School(15) and those of 5th grade in B Elementary School(20). The summary of this paper's results are as follows. First, in order to compose remote observatory system, an astronomical telescope available for remote control to transfer actual observed images in real-time was manufactured. Second, learning program for using remote observatory system wad developed by selecting contents through analysis of the curriculum. Third, in order to figure out effects of astronomical observation program using remote observatory program on scientific investigation ability and attitude of science-gifted elementary students. As a result, both of basic investigation ability and integrated investigation abilit, sub-elements of scientific investigation ability, showed significant differences and scientific investigation ability combining basic and integrated investigation abilities showed significant differences as well. Effects of astronomical observation program applying remote observatory also showed significant differences and its sub-elements, openness, collaboration, patience and creativeness did not show significant differences while curiosity, critics and volunteering showed significant differences.

• Journal of Aerospace System Engineering
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• v.12 no.4
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• pp.75-80
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• 2018

The working principle of a satellite camera involves a focusing mechanism for controlling the focus of the optical system, which is essential for proper functioning. However, research on focusing mechanisms of satellite optical systems in Korea is in the beginning stage and developed technology is limited to a thermal control type. Therefore, in this paper, we propose a motor-driven focusing mechanism applicable to small satellite optical systems. The proposed mechanism is designed to generate z-axis displacement in the secondary mirror by a motor. In addition, three flexure hinges have been installed on the supporter for application of preload on the mechanism resulting in minimization of the alignment error arising due to manufacturing tolerance and assembly tolerance within the mechanism. After fabrication of the mechanism, the alignment errors (de-space, de-center, and tilt) were measured with LVDT sensors and laser displacement meters. Conclusively, the proposed focusing mechanism could achieve proper alignment degree, which can be applicable to small satellite optical system.

• Korean Journal of Optics and Photonics
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• v.13 no.5
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• pp.442-448
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• 2002

In the earth telescope for space observation, the adaptive optical (AO) system that immediately compensates atmospheric turbulence is helpful to get high-resolution images. An adaptive optics for earth telescopes is very attractive, since the Earth telescopes can be made at lower costs and have larger optical apertures than space telescopes. Generally. in order to remove the wavefront error produced by atmospheric turbulence, a deformable mirror, whose surface shape changes in a controllable way in response to a drive signal, is used. The characteristics and patterns of actuators are very important for the effective control of a deformable mirror. The mirror surface shape deformed by one actuator is defined as an influence function and the deformable mirror can be effectively modeled and designed using this influence function. In this paper. by simplifying the actual influence function obtained by FEM analyses into the Gaussian function and introducing the coupling coefficient between actuators, the influence function is constructed. The proper coupling coefficient of the target system can be obtained by performance analyses of a deformable mirror for various coupling coefficients. Using the constructed influence function, the deformable mirror with equally spaced triangular and square actuator patterns is analyzed for various spacings and an effective actuator pattern is proposed.