• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.1
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• pp.92-99
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• 2008

KOMSAT-5 will attach an laser retroreflector array for precise orbit determination. Laser retroreflector array was developed by DFZ in Germany and have pyramid type composed of four corner cube prisms. In this paper, the performance analyses as effective area of retroreflector and photons measured by link budget and position of ground station were performed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.1
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• pp.58-66
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• 2003

This paper discusses the practical issue of the bias estimation of the KOREASAT ground tracking data. First, a batch filter based orbit determination algorithm including the turn around range measurement in addition to the range, azimuth and elevation measurement is presented. Then the estimation performance is analyzed through simulation studies. Additionally, this paper proposes a tracking antenna bias estimation strategies using accurately tuned secondary ground tracking station. Finally the relationship between antenna biases are analyzed to give comprehensive tool for estimation results evaluation.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.152.1-152.1
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• 2008

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.59-59
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• 2004

• Bulletin of the Korean Space Science Society
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• 2002.05b
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• pp.40-40
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• 2002

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2005.02a
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• pp.41-50
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• 2005

• ETRI Journal
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• v.25 no.5
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• pp.387-400
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• 2003

Since its launching on 21 December 1999, the Korea Multi-Purpose Satellite-I (KOMPSAT-I) has been successfully operated by the Mission Control Element (MCE), which was developed by the ETRI. Most of the major functions of the MCE have been successfully demonstrated and verified during the three years of the mission life of the satellite. This paper presents the operational performances of the various functions in MAPS. We show the performance and analysis of orbit determinations using ground-based tracking data and GPS navigation solutions. We present four instances of the orbit maneuvers that guided the spacecraft form injection orbit into the nominal on-orbit. We include the ground-based attitude determination using telemetry data and the attitude maneuvers for imaging mission. The event prediction, mission scheduling, and command planning functions in MAPS subsequently generate the spacecraft mission operations and command plan. The fuel accounting and the realtime ground track display also support the spacecraft mission operations.

• Journal of Positioning, Navigation, and Timing
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• v.8 no.4
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• pp.201-208
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• 2019

Numerical integration is necessary for satellite orbit determination and its prediction. The numerical integration algorithm can be divided into single-step and multi-step method. There are lots of single-step and multi-step methods. However, the Runge-Kutta method in single-step and the Adams method in multi-step are generally used in global navigation satellite system (GNSS) satellite orbit. In this study, 4th and 8th order Runge-Kutta methods and various order of Adams-Bashforth-Moulton methods were used for GLObal NAvigation Satellite System (GLONASS) orbit integration using its broadcast ephemeris and these methods were compared with international GNSS service (IGS) final products for 7days. As a result, the RMSE of Runge-Kutta methods were 3.13m and 4th and 8th order Runge-Kutta results were very close and also 3rd to 9th order Adams-Bashforth-Moulton results. About result of computation time, this study showed that 4th order Runge-Kutta was the fastest. However, in case of 8th order Runge-Kutta, it was faster than 14th order Adams-Bashforth-Moulton but slower than 13th order Adams-Bashforth-Moulton in this study.

• Journal of Power Electronics
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• v.6 no.1
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• pp.18-28
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• 2006

The Electric Power Subsystem (EPS) is one of the most critical systems on any satellite because nearly every subsystem requires power. This makes the choice of power systems the most important task facing satellite designers. The main purpose of the Satellite EPS is to provide continuous, regulated and conditioned power to all the satellite subsystems. It has to withstand radiation, thermal cycling and vacuums in hostile space environments, as well as subsystem degradation over time. The EPS power characteristics are determined by both the parameters of the system itself and by the satellite orbit. After satellite separation from the launch vehicle (LV) to its orbit, in almost all situations, the satellite subsystems (attitude determination and control, communication and onboard computer and data handling (OBC&DH)), take their needed power from a storage battery (SB) and solar arrays (SA) besides the consumed power in the EPS management device. At this point (separation point, detumbling mode), the satellite's angular motion is high and the orientation of the solar arrays, with respect to the Sun, will change in a non-uniform way, so the amount of power generated by the solar arrays will be affected. The objective of this research is to select satellite EPS component types, to estimate solar array illumination parameters and to determine the efficiency of solar arrays during both detumbling and normal operation modes.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.2
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• pp.149-157
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• 2009

The orbit ephemeris of Global Positioning System(GPS) is one element to determine the surveying accuracy and there are broadcasting ephemeris and precise ephemeris, IGS rapid orbit and IGS ultra rapid orbit in the orbit ephemeris of GPS. In this study, test area was selected in Uljin, Kyungsanbukdo and GPS surveying was accomplished at 37 points in the test area. Then baseline solution was done on 74 baseline using broadcasting ephemeris and precise ephemeris and analysis by TGO and the results were compared. Comparison results were showed that there were nearly no difference between the two results but in case of relative precision of the baseline, it was slightly better the baseline results of precise ephemeris which showed 0.706ppm than the baseline results of broadcasting ephemeris which showed 0.708ppm.