• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.707-708
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.523-524
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.129-130
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• 2011

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1223-1224
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• 2011

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1225-1226
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• 2011

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.1
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• pp.81-89
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• 2011

The previous land gravity data in Korea showed locally biased irregular distribution. Especially, this problem was more serious in the mountainous area where the data density was significantly low. The same problem appeared in GPS/Levelling data thus the precision of the geoid could not be improved. From 2008, new gravity and GPS/Levelling data has been collected by the unified control point and survey on the benchmark project which were funded by the national geographic information institute. The newly obtained data has much better distribution and precision so that it could be used for update precision of geoid model. In this study, the new precision geoid has been calculated based old and new gravity data and this model showed 5.29cm of precision compared to 927 points of GPS/Levelling data. And the degree of fit and precision of hybrid geoid has been calculated 2.99cm and 3.67cm. The new gravimetric geoid has been updated about 27% over whole country. And it showed 42% of precision update due to collection of new gravity data on the Kangwon/Kyeongsang area which showed quite low distribution. In 2010, about 4,000 points of gravity and 300 points of GPS/Levelling data has been obtained by unified control and survey on benchmark project. We expect that new data will contribute to updating geoid precision and veri tying precision more objectively.

• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.221-228
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• 2005

In this study, orbit prediction accuracy of the MPAS for the KOMPSAT-2 was analyzed in order to verify the TPF accuracy and operate the APS of the KOMPSAT-2 successfully. The analysis was performed using flight data of the KOMPSAT-1 in that the KOMPSAT-2 will be operated in the same orbit of the KOMPSAT-1. The periods to analyze were selected according to the solar activity. The results in this study verified the requirement for the TPF accuracy and will be used for the successful operation of the KOMPSAT-2.

• Journal of Astronomy and Space Sciences
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• v.19 no.4
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• pp.385-394
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• 2002

Satellite laser ranging is a technique for precisely measuring the range between a laser station and a satellite that is equipped with retro-reflectors. SLR technique was first used for Beacon-B satellite in 1964 with the ranging accuracy of meter level. Now the single shot have centimeter level accuracy and the normal point have mm level in ranging. In this study we developed the algorithm for precise orbit determination using SLR data and performed the orbit determination of GPS-36 satellite using the algorithm. RMS of the estimated orbit was 74cm when compared with IGS precise orbit. It is known that RMS of SLR measurement residual is below 55mm. But we were able to achieve 44mm RMS of residual throughout this study.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.9 no.2
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• pp.73-80
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• 1991

Identifying linear form of the parts of precision machine, precise monitoring is indispensable. Therefore, in this study, close-range photogrammetry being tried to screw one of the parts of precision machine, using non-metric camera that is calibrated by plumb line method. Also, it is analyzed three dimensional values of tortien, offset, section and thickness. From results of this study, monitoring of the parts of precision machine was conducted efficiently using non-metric camera and possibility of this application was proved.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.161.2-161.2
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• 2012

위성의 지향 정밀도에 영향을 주는 요소로 정밀한 자세명령을 생성해 주어야 하는데, 정밀 자세 명령을 생성하기 위해서는 기준좌표계를 잘 결정해야 한다. 저궤도 위성의 기준좌표계는 GPS위성으로부터 수신한 위성의 위치와 속도 및 시각 정보로부터 기준 시각의 좌표계를 생성하게 된다. 정지궤도 위성의 경우에는 GPS 위성을 사용하기 어려우므로 계속 지상에서 궤도 정보를 올려주거나 탑재 컴퓨터에 궤도전파기나 궤도 결정 알고리즘을 탑재하여 위성의 궤도 정보를 계산하게 된다. 본 연구는 정지궤도 위성의 궤도정보 요구사항을 분석하고 이를 만족하는 궤도전파기/궤도 생성 알고리즘의 개념 설계를 목적으로 한다. 먼저 저궤도위성에서 사용한 방법으로 GPS 위성으로부터 수신한 궤도 정보를 바탕으로 내부 탑재 궤도전파기를 사용하여 실제 궤도 정보가 이용되는 시간까지 궤도 정보를 전파하여 기준좌표계를 생성하는 방법을 검토하였다. 그 다음 기존의 정지궤도 위성에서 사용한 탑재 궤도 전파기/궤도 결정 알고리즘을 검토하고 새로 개발하는 정지궤도 위성의 특성을 고려하여 궤도 정밀도 요구사항을 분석하고 이를 만족하는 탑재 궤도 전파기를 설계하였다. 마지막으로 시뮬레이션을 통해 요구조건 만족과 설계 결과를 검증하였다.