• Publications of The Korean Astronomical Society
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• v.11 no.1
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• pp.57-73
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• 1996

As a continuing effort to develop an automatic control system for small telescope, we developed the software for telescope control and CCD observations under DOS operating system. For accurate pointing of the telescope in short amount of time, we modelled the angular speed of the telescope by aquadratic function of time (constant acceleration) for the first 15 second and then linear function of time (zero acceleration) aftwewards. By changing the telescope speed from 'slew' to 'fine' before the telescope reaches the desired position, we could achieve the accuracy of a few arcsecond. The CCD control software was written for model CCD-10 of CCD Technology. This CCD can be used for guiding purposes. We also conducted the study for remote control of the telescope using telephone line. Although it cannot be used for real observations at the present form, we succeded in remotely pointing the telescope to desired direction. As faster communication technologies become widely available, simple observations can be made remotely in the near future. Finally we report some observational results made with the present control system.

• Publications of The Korean Astronomical Society
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• v.21 no.2
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• pp.81-86
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• 2006

Even though 30inch optical telescope at Kyung Hee Astronomy Observatory has been used to produce a series of scientific achievements since its first light in 1992, numerous difficulties in operating of the telescope have hindered the precise observations needed for further researches. Since the currently used PC-TCS(Personal Computer based Telescope Control System) software based on ISA-bus type is outdated, it doesn't have a user friendly interface and make it impossible to scale. Also accumulated errors which are generated by discordance from input and output signals into a motion controller required new control system. Thus we have improved the telescope control system by updating software and modifying mechanical parts. We applied a new BLDC(brushless DC) servo motor system to the mechanical parts of the telescope and developed a control software using Visual Basic6.0. As a result, we could achieve a high accuracy in controlling of the telescope and use the user friendly GUI(Graphic User Interface).

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.3
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• pp.224-229
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• 2012

In this paper, we propose a correction method for astronomical telescope using recursive least square method. There are two ways to move a telescope : equatorial operation and altazimuth operation. We must align polar axis of a equatorial telescope with the north celestial pole and adjust the horizontal axis of a altazimuth telescope exactly to match the celestial coordinate system with the telescope coordinate system. This process needs time and expertise. We can skip existing process and correct a tracking error easily by deriving the relationship of the celestial coordinate system and the telescope coordinate system using the proposed correction method. We obtain the coordinate of a celestial body in the celestial coordinate system and the telescope coordinate system and derive a transformation matrix through the obtained coordinate. We use recursive least square method to estimate the unknown parameters of a transformation matrix. Finally, we implement a telescope control system using a microprocessor and verify the performance of the correction method. Through an experiment, we show the validity of the proposed correction method.

• Publications of The Korean Astronomical Society
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• v.13 no.1 s.14
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• pp.85-98
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• 1998

In this paper we describe MS-TCS, the telescope control system which was developed in Korea Astronomy Observatory. MS-TCS can control an equatorial type telescope equipped with stepping motors and incremental type optical encoders. MS-TCS consists of (1) POINT_TEL which is the program roning in a PC and (2) TCS-196 which is the electroics board to control the telescope. The communication between the PC and TCS-l96 is done through RS-232 or RS-422 serial line. MS-TCS can control the secondary mirror and dome. It also provide network function using TCP/IP for remote control of the telescope. MS-TCS is suitable for controlling medium to small size telescope for research and education.

• Journal of Astronomy and Space Sciences
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• v.21 no.2
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• pp.121-128
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• 2004

As the first step of the real time monitoring system of the solar radio disturbance, we constructed the control system of the solar radio telescope. An 1.8m antenna built by Korean Astronomy Observatory has been used, and the observed radio flux is transformed to the digital signal by the powermeter. We have also developed a computer program CBNUART in order to control the telescope system and the powermeter. As the sun rises, the telescope begins to observe the sun, and ends the observation automatically at sunset. The CBNUART enables the telescope automatically to go to the position of the sunrise for the beginning the observation and come back to the setposition after the ending the observation at the sunset. An active tracking routine is adopted in order to improve the tracking accuracy of the control system, and we used an optical telescope equipped in front of the antenna for control test. The tracking test shows that our control system can track with the accuracy of arc seconds, and the 50 minute pointing test shows that the pointing accuracy of right ascension and declination are 1.12 and 0.08 arc minutes respectively.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.72.1-72.1
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• 2019

The Giant Magellan Telescope Organization (GMTO) is developing the GMT Software Development Kit (SDK) for the Observatory Control System (OCS). The SDK models a subsystem of the GMT using a Domain Specific Language (DSL) which can generate a skeleton code and validates the availability of the model automatically. The OCS includes a Device Control System (DCS) and all the devices are connected with the DCS via EtherCAT. The DCS has a component (Hardware Adapter) to communicate with EtherCAT slaves. In this presentation, we demonstrate the modeling process and describe the importance and usage plan of the SDK.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.6
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• pp.745-751
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• 2013

In naval gun firing, firing accuracy comes from the combination of each component's accuracy in CFCS (Command and Fire Control System) like tracking sensors and gun. Generally, battery alignment is done to correct the error between gun and tracking sensor by using boresight telescope on harbor and sea. But normally, the battery alignment can compensate only the static alignment error and ignore dynamic alignment error which is caused by own ship movement. There was no research on this dynamic alignment error until now. We propose a new way to analyze dynamic arrangement error by using image of boresight telescope. In case of the dynamic alignment error was due to time delay of own ship attitude information, we propose the way to compensate it.

• Publications of The Korean Astronomical Society
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• v.14 no.1
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• pp.47-56
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• 1999

We have improved the control and driving system of 16' reflector at Kwanak Observatory at Seoul National University, by completing encoder unit, and by developing programs for correction of errors resulting from hardware defects. The hardware defects of this telescope system are the large backlash and the nonuniform tracking and pointing. The telescope pointing accuracy for RA is improved to a few arc minutes, and that for DEC is several tens of arc minutes. The guiding error is improved to 0.7 arcsec/minute, allowing up to 3 minutes exposure for CCD imaging under typical seeing conditions at the Observatory.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.78.2-78.2
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• 2019

The temperature control of a scientific device is essential because extreme temperature conditions can cause hazard issues for the operation. We developed a software which can interact with the temperature sensor using the GMT SDK(Giant Magellan Telescope Software Development Kit) version 1.6.0. The temperature sensor interacts with the EtherCAT(Ethernet for Control Automation Technology) slave via the hardware adapter, sending and receiving data by a packet. The PDO(Process Data Object) and SDO(Service Data Object), which are the packet interacts with each EtherCAT slave, are defined on the TwinCAT program that enables the real-time control of the devices. The user can receive data from the device via grs(GMT Runtime System) tools and log service. Besides, we programmed the software to print an alert message on the log when the temperature condition changes to certain conditions.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.395-396
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• 1996

We developed a telescope control system called ASTROS for the VST1 and VST2, which are specially designed radio telescopes to make a survey and have a 60-cm main dish. ASTROS is designed on the distributed intelligence concept and structurized programming. The hardware of the system is composed of several intelligent devices connected with de facto standard interfaces and main control unit is PC. The program is coded in the C language and its structure is object oriented in order to make easy to replace the component devices. ASTROS is now running on two twin telescopes, VST1 and VST2. VST1 is installed at Nobeyama in Japan and VST2 is installed at La Silla in Chile. They are making a galactic plane survey in CO (J=2-1) with 9 arcmin beam semi-automatically.