• Journal of the Korean Solar Energy Society
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• v.34 no.5
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• pp.53-63
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• 2014

Caltech's Linde-Robinson Laboratory was originally built in 1932 featuring a Spanish mission-style design, whose function was to facilitate a solar observatory with a coelostat solar telescope dome and a solar shaft extending from the roof to more than 36.58m below the ground. The building has now been transformed into a cutting-edge center for research and instruction in global environmental science that retains its original character while setting new standards in energy efficiency and green design. It is the first LEED Platinum lab in the USA for renovation of a historical research building, consuming only one-sixth of the energy that the lab's comparable laboratories do. This work introduces various energy and environmental strategies hired for its sustainable rehabilitation and, especially, examines the functional validity of solar telescope daylighting by a coelostat. Observations were made on the llumination of underground floors, where illuminances of 40~50 lx were measured.

• Journal of The Korean Astronomical Society
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• v.51 no.6
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• pp.207-214
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• 2018

A coelostat is often used for solar observations, because it corrects the image rotation automatically by guiding sunlight into a fixed telescope with two plane mirrors. For the purposes of education and spectroscopic observation, the solar group at Seoul National University (SNU) plans to develop the SNU coelostat (SNUC) and install it in the SNU Astronomical Observatory (SAO). Requirements of the SNUC are < 1" positioning accuracy with 30 cm beam size on the entrance pupil in the compact dome. To allow for installation in the small dome, we design a compact slope type coelostat with a 45 cm primary plane mirror and a 39 cm secondary plane mirror. The motion of the SNUC is minimized by fixing the position of the slope frame. Numerical simulations of the available observational time of the designed coelostat shows that the sun can be observed ay all times from June to early August and at least three hours in other months. Since the high accuracy driving motors installed in the SNUC can be affected by external environment factors such as humidity and temperature variations, we design a prototype to test the significance of these effects. The prototype consists of a 20 cm primary plane mirror, a 1 m slope rail, a direct drive motor, a ballscrew, a linear motion guide, an AC servo motor, a reduction gear and a linear encoder. We plan to control and test the accuracy of the prototype with varying atmospheric conditions in early 2019. After testing the prototype, the SNUC will be manufactured and installed in SAO by 2020.

• Publications of The Korean Astronomical Society
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• v.18 no.1
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• pp.61-67
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• 2003

In 2002, a new solar spectroscopic system with the Coelostat type has been installed at Korea Astronomical Observatory. It was designed to observe solar spectra in the range from 3000 to 8000${\AA}$ with the spectral resolution of 1${\AA}$/mm. The system is composed of a 40cm diameter Coelostat with 9m focal length, spectroscopic system with 600groove/mm grating, and a IK ${\times}$ IK CCD detector. By developing observational softwares for this system, we have successfully observed solar Ha spectra. In this paper, we development of telescope control and observational softwares.