• The Bulletin of The Korean Astronomical Society
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• v.31 no.1
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• pp.57.1-57.1
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• 2006

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.75.2-75.2
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• 2016

We introduce Korean involvement in the Large Synoptic Survey Telescope Project and activities organized by a group of Korean astronomers as LSST Korea. The Korea Astronomy and Space Science Institute plans to sign a memorandum of agreement with Large Synoptic Survey Telescope Corporation this year. Although the project will start its commissioning observation around 2020, Korean preparation for the LSST era should be initiated now because of an unprecedented amount of data produced in the LSST. We explain current status of our efforts for the LSST Korea.

• Journal of Space Technology and Applications
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• v.1 no.1
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• pp.104-120
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• 2021

Some optical schemes of lenses for spacecraft developed by the author are considered. The main optical characteristics of telescope lenses of various architectures are compared. We propose compact solutions of mirror, lens-mirror, and lens systems with maximum available angular resolutions and other parameters. Examples of calculating the optical systems of lenses used for various tasks both in the field of astronomy and in the field of remote sensing of the Earth and other planets are given. The example of onboard computer system is discussed. Practical recommendations on the development and use of telescope lenses are given.

• Journal of the Korean Mathematical Society
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• v.59 no.2
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• pp.379-405
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• 2022

We introduce the notions of Koszul N-complex, Čech N-complex and telescope N-complex, explicit derived torsion and derived completion functors in the derived category D_N (R) of N-complexes using the Čech N-complex and the telescope N-complex. Moreover, we give an equivalence between the categories of cohomologically 𝖆-torsion N-complexes and cohomologically 𝖆-adic complete N-complexes, and prove that over a commutative Noetherian ring, via Koszul cohomology, via RHom cohomology (resp. ⊗ cohomology) and via local cohomology (resp. derived completion), all yield the same invariant.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.225-228
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• 2005

Telescope structure based on Korsch type optical layout was suggested for a large aperture optical system. Korsch type optical layout is regarded as providing wide field of view and no color aberration for which high resolution space cameras greatly demand. For the suggested Korsch type telescope structure, two folding mirrors are adopted, firstly to provide for the refocusing device mounting plane on the second fold mirror assembly, secondly by double folding the light path to concisely confine focal plane assembly within the perimeter of the tube. Optical layput design and corresponding support structure design were attained.

• Bulletin of the Korean Space Science Society
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• 2005.10a
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• pp.149-152
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• 2005

High-resolution telescope from space comprises electro-optical imagery with a ground resolution tying within the range of 1 to 5 meters. According to information documented in the literature up to now, most primary mirrors verified and flown in optical space missions have been lightweighted made from Zerodur, ULE, beryllium, SiC or aluminium. A trade off study was performed to determine as a &lightweighted& by factors like backside cell pattern, rib thickness, face thickness, mirror fixation device location and material and so on based on structural performance for primary mirror in submeter class spaceborne telescope.

• Publications of The Korean Astronomical Society
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• v.13 no.1 s.14
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• pp.65-73
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• 1998

We installed windscreen at the BOAO 1.8m telescope dome, in order to reduce the degradation of image Quality under strong wind larger than 8m/sec. The windscreen was designed on the basis of that installed at the MSSSO 2.3m telescope dome in Australia. We developed control system (remote control and user program) of the windscreen, being able to operate the windscreen at observation room. We tested the performance of the windscreen under strong wind of 6-15m/see. Tracking error of the telescope, especially in altitude-axis, was greatly decreased when the windscreen was used. Standard deviation of the error was estimated to be less than 0.3arcsec, which has little effect on image quality.

• Publications of The Korean Astronomical Society
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• v.20 no.1 s.24
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• pp.73-83
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• 2005

On-The-Fly (OTF) observation method is developed for the efficient use of 6 M radio telescope at Seoul Radio Astronomy Observatory (SRAO). This technique, in which data and information of antenna position are recorded synchronously while driving a telescope regularly and rapidly across a field, provides more efficient use of telescope time and better calibration of the acquired data than the traditional point-to-point observation method does. For the realization of the method, we (1) added RT-Linux modules to the existing operating system, (2) replaced digital voltmeter with voltage-to-frequency converter, and (3) modified many SRAO observation programs. By observing Moon and G78.2+2.7 using this method and comparing them with previous observations, we verify the successful operation and efficiency of the OTF observation mode.

• Publications of The Korean Astronomical Society
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• v.19 no.1
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• pp.71-76
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• 2004

We have developed a tool for measuring optical aberrations of telescope. We adopt curvature sensing technique and use the least square method for finding the amplitudes of the Zernike polynomials. This tool runs under the PC Linux system and the PC windows system with Linux emulators such as Cygwin. The program for UNIX system is used for optical alignment of 1.8M optical telescope at the Bohyunsan Optical Astronomical Observatory (BOAO) and the PC based program is used for the Korea Astronomy Observatory (KAO) wide field telescope (named NEOPAT-3). Our tool is found to be efficient for precise measurement of the optical aberrations of telescopes.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.35.4-36
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• 2017

A 250 kton water Cherenkov detector is proposed to be built in Korea to determine the CP violation phase and the neutrino mass ordering using a neutrino beam produced in J-PARC of Japan. It will be also a world-leading neutrino telescope to reveal the mystery of supernova explosion by observing a neutrino burst. The telescope is expected to detect more than 100,000 neutrinos in ten seconds from a supernova explosion in our Galaxy. The pointing accuracy will be better than 1 degree and be able to guide early optical telescope observations. The expected rate of supernova explosion in our galaxy is once per every 30 years in the most optimistic case or once per every 100 years in the worst case. If it is indeed observed, it will be a historical chance to study the supernova explosion mechanism in great details. In this talk, various astronomy potentials will be discussed if the Korean neutrino observatory is built.