• Journal of Astronomy and Space Sciences
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• 제23권2호
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• pp.143-152
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• 2006

밝은 장주기 변광성들을 효율적으로 관측하기 위하여 충북대학교 교내에 자동관측시스템을 구축하였다. 이 시스템의 구성을 위하여 기존의 Meade사 LX200 40cm 망원경의 구동부를 개선하고, ObsTool II라는 관측프로그램에 의하여 망원경, CCD 카메라, 돔의 제어가 하나의 프로그램으로 가능하도록 구성하였다. ObsTool II는 COM(Common Object Module)을 이용하여 개발한 프로그램으로서 시스템을 구성하는 망원경이나 CCD 카메라의 기종이 바뀌어도 큰 수정 없이 시스템을 재구성할 수 있다. 또한, 이 시스템은 광전측광관측처럼 변광성, 비교성, 검토성 등을 오가는 기능을 가지고 있어 CCD의 시야에 적당한 비교성이 함께 들어오지 않더라도 관측이 가능하다. 이 논문에서 새롭게 구성한 자동관측시스템의 안정성을 검토하기 위하여 W UMa형 변광성 V523 Cas와 자기 격변변광성 TT Ari를 관측하여 그 결과를 제시하면서 본 논문에서 개발한 시스템들의 활용가능성을 토의하였다.

• 천문학회지
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• 제48권3호
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• pp.177-185
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• 2015

We develop a new auto-guiding system for the Camera for QUasars in the EArly uNiverse (CQUEAN). CQUEAN is an optical CCD camera system attached to the 2.1-m Otto-Struve Telescope (OST) at McDonald Observatory, USA. The new auto-guiding system differs from the original one in the following: instead of the cassegrain focus of the OST, it is attached to the finder scope; it has its own filter system for observation of bright targets; and it is controlled with the CQUEAN Auto-guiding Package, a newly developed auto-guiding program. Finder scope commands a very wide field of view at the expense of poorer light gathering power than that of the OST. Based on the star count data and the limiting magnitude of the system, we estimate there are more than 5.9 observable stars with a single FOV using the new auto-guiding CCD camera. An adapter is made to attach the system to the finder scope. The new auto-guiding system successfully guided the OST to obtain science data with CQUEAN during the test run in 2014 February. The FWHM and ellipticity distributions of stellar profiles on CQUEAN, images guided with the new auto-guiding system, indicate similar guiding capabilities with the original auto-guiding system but with slightly poorer guiding performance at longer exposures, as indicated by the position angle distribution. We conclude that the new auto-guiding system has overall similar guiding performance to the original system. The new auto-guiding system will be used for the second generation CQUEAN, but it can be used for other cassegrain instruments of the OST.

• 천문학회지
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• 제37권4호
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• pp.179-184
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• 2004

We have developed a wide-field imaging camera system, called WICZO, to monitor light of the night sky over extended period. Such monitoring is necessary for studying the morphology of interplanetary dust cloud and also the time and spatial variations of airglow emission. The system consists of an electric cooler a CCD camera with $60\%$ quantum efficiency at 500nm, and a fish-eye lens with $180^{\circ}$ field of view. Wide field imaging is highly desired in light of the night sky observations in general, because the zodiacal light and the airglow emission extend over the entire sky. This paper illustrates the design of WICZO, reports the result of its laboratory performance test, and presents the first night sky image, which was taken, under collaboration with Byulmaro Observatory, on top of Mt. Bongrae at Yongweol in January, 2004.

• 천문학회지
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• 제43권3호
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• pp.75-93
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• 2010

We present the characteristics of the Seoul National University 4k Camera (SNUCAM) and report its performance on the 1.5m telescope at the Maidanak observatory in Uzbekistan. SNUCAM is a CCD camera with a pixel scale of 0.266" in $4096{\times}4096$ format, covering $18.1'{\times}18.1'$ field of view on the 1.5m. The camera is currently equipped with Bessell UBVRI, $H{\alpha}$, SDSS ugriz, and Y-band filters, allowing us to carry out a variety of scientific programs ranging from exoplanet studies to survey of quasars at high redshift. We examine properties of SNUCAM such as the bias level and its temporal variation, the dark current, the readout noise, the gain, the linearity, the fringe patterns, the amplifier bias, and the bad pixels. From our observations, we also constructed the master fringe frames in I-, z-, and Y-band. We outline some of the current scientific programs being carried out with SNUCAM, and demonstrate that SNUCAM on the 1.5m can deliver excellent images that reach to the $5-{\sigma}$ detection limits of R~25.5 mag and z~22.7 mag in 1 hour total integration.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.549-552
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• 2012

This report presents a mobile instrumentation platform based on a smartphone using its built-in functions for colorimetric diagnosis. The color change as a result of detection is taken as a picture through a CCD camera built in the smartphone, and is evaluated in the form of the hue value to give the well-defined relationship between the color and the concentration. To prove the concept in the present work, proton concentration measurements were conducted on pH paper coupled with a smartphone for demonstration. This report is believed to show the possibility of adapting a smartphone to a mobile analytical transducer, and more applications for bioanalysis are expected to be developed using other built-in functions of the smartphone.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1894-1898
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• 1991

A landmark tracking system(LTS) has been developed for use in locating objects in a manufacturing environment. The Landmark Tracking System is an integrated system which consists of a grey scale CCD camera, an image processor, an illumination system based on electronic flash, and software intended primarily for tracking retroreflective landmarks. The term "integreated" means that the camera electronics and the strobe electronics are directly linked to the computer system, governed by the same clock and under direct software control. A novel element in the LTS is that a pinhole is used for the optics.he optics.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2313-2316
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• 2004

Accurate calibration effect for maladjusted stereo cameras with calibrated pixel distance parameter is presented. The camera calibration is a necessary procedure for stereo vision-based depth computation. Intra and extra parameters should be obtain to determine the relation between image and world coordination through experiment. One difficulty is in camera alignment for parallel installation: placing two CCD arrays in a plane. No effective methods for such alignment have been presented before. Some amount of depth error caused from such non-parallel installation of cameras is inevitable. If the pixel distance parameter which is one of intra parameter is calibrated with known points, such error can be compensated in some amount and showed the variable experiments for accurate effects.

• 천문학회지
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• 제46권4호
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• pp.161-172
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• 2013

A focal reducer is developed for CQUEAN (Camera for QUasars in EArly uNiverse), which is a CCD imaging system on the 2.1 m Otto Struve telescope at the McDonald observatory. It allows CQUEAN to secure a wider field of view by reducing the effective focal length by a factor of three. The optical point spread function without seeing effects is designed to be within one pixel ($0.283^{\prime\prime}$) over the field of view of $4.82^{\prime}{\times}4.82^{\prime}$ in optimum wavelength ranges of 0.8-1.1 ${\mu}m$. In this paper, we describe and discuss the characteristics of optical design, the lens and barrel fabrications and the alignment processes. The observation results show that the image quality of the focal reducer confirms the expectations from the design.

• 천문학회지
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• 제56권2호
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• pp.169-185
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• 2023

The GMT-Consortium Large Earth Finder (G-CLEF) is the first instrument for the Giant Magellan Telescope (GMT). G-CLEF is a fiber feed, optical band echelle spectrograph that is capable of extremely precise radial velocity measurement. G-CLEF Flexure Control Camera (FCC) is included as a part in G-CLEF Front End Assembly (GCFEA), which monitors the field images focused on a fiber mirror to control the flexure and the focus errors within GCFEA. FCC consists of an optical bench on which five optical components are installed. The order of the optical train is: a collimator, neutral density filters, a focus analyzer, a reimager and a detector (Andor iKon-L 936 CCD camera). The collimator consists of a triplet lens and receives the beam reflected by a fiber mirror. The neutral density filters make it possible a broad range star brightness as a target or a guide. The focus analyzer is used to measure a focus offset. The reimager focuses the beam from the collimator onto the CCD detector focal plane. The detector module includes a linear translator and a field de-rotator. We performed thermoelastic stress analysis for lenses and their mounts to confirm the physical safety of the lens materials. We also conducted the global structure analysis for various gravitational orientations to verify the image stability requirement during the operation of the telescope and the instrument. In this article, we present the opto-mechanical detailed design of G-CLEF FCC and describe the consequence of the numerical finite element analyses for the design.

• 천문학논총
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• 제15권spc1호
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• pp.119-126
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• 2000

The BOES (BOAO Echelle Spectrograph), a fiber-fed echelle spectrograph of the BOAO 1.8 m telescope, has been designed and now is being manufactured. The BOES follows a white pupil design collimated with two off-axis parabolic mirrors. The 136mm collimating beam leaving the 41.59 grooves/mm R4 echelle grating is refocused near the narrow folding mirror. Through the two cross-disperser prisms and $\phi250 mm(f/1.5)$ transmission camera, the beam images on EEV $2k\times4k$ CCD. The BOES can take the wavelength range of 3700 to $10100{\AA}$ at a single spot with spectral resolution R = 20000 to 40000 depending on the fiber set employed. We describe the key sciences and performance, current status of construction, and future plan of the BOES.