• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.228-231
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• 2008

For a satellite data communication, the technology of frame synchronization is widely used between a sender and a receiver. Last year, we suggested zero-loss frame synchronization [1] using pattern search and using bits threshold search algorithm that is based on SIMD technology [2,3]. This algorithm could solve both of hardware and software drawbacks, which are frame loss and low processing performance. However, this algorithm didn't optimize the processing of output data, synchronized data, which caused overhead to the memory allocation and the memory copy. Consequently, the performance of the frame synchronizer application was degraded. In this paper, we enhance previous work using a circular buffer in order to optimize the output data processing. The performance comparison with the previous algorithm shows that the enhanced proposed approach dramatically outperforms in the output data processing speed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.12
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• pp.1103-1111
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• 2016

Korea Astronomy and Space Science Institute (KASI) has been operating SLR (Satellite Laser Ranging) system with 2kHz repetition rate for satellite precise orbit and spin determination as well as space geodesy. But the SLR system was improved to be capable of laser ranging with high repetition rate, up to 10kHz by developing new operation software and novel range gate generator, called HSLR-10. The HSLR-10 will contribute to the accurate spin rate determination of geodetic satellites and geodetic research due to its largest repetition rate in the world. In this study, the development methodology and configuration of operation software are addressed, and its validation results are also presented.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.158-159
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• 2023

With the development and state-of-the-art of ocean satellites, wide-area management of the waters around Korea has become possible. In particular, in the field of ship operation, as autonomous navigation technology based on artificial intelligence and big data is being developed, there is a need for additional analysis and observation through ocean satellite data.. Researches that can combine ship operation with ocean satellite data include ship detection based on ocean satellites and ship navigation assistance using marine weather forecasting.

• The Bulletin of The Korean Astronomical Society
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• v.24 no.2
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• pp.71-71
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• 1999

• 한국전산유체공학회:학술대회논문집
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• 2007.10a
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• pp.227-231
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• 2007

COMS (Communication, Ocean and Meteorological Satellite) is a geostationary satellite and has been developing by KARI for communication and ocean and meteorological observations. It will be launched by ARIANE 5. Ka-band components are installed on South panel, where single solar array wing is mounted. Radiators, embedded heat pipes, external heat pipe, insulation blankets and heaters are utilized for the thermal control of the satellite. The Ka-band payload section is divided several areas based on unit operating temperature in order to optimize radiator area and maximize heat rejection capability. Other equipment for sensors and bus are installed on North panel. The ocean and meteorological sensors are installed on optical benches on the top floor to decouple thermally from the satellite. During the transfer orbit operation, satellite will be under severe thermal environments due to low dissipation of components, satellite attitudes and LAE(Liquid Apogee Engine) firing. This paper presents temperature and heater power prediction and validation of thermal control design during transfer orbit operation.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.33-36
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• 1999

The KOMPSAT, which is scheduled to be launched by Taurus launch vehicle in late November of 1999, will be in a sun-synchronous orbit with an altitude of 685km, eccentricity of 0.001, inclination of 98deg and local time of ascending node of 10:50 a.m. Electronics and Telecommunications Research Institute and Daewoo Heavy Industry had jointly developed a KOMPSAT Simulator as a component of the KOMPSAT Mission Control Element. The MCE had been delivered to Korea Aerospace Research Institute for the KOMPSAT ground operation. It is being used for training of KOMPSAT ground station personnel. Each of satellite subsystems and space environment were mathematically modeled in the simulator. To verify the overall function of KOMPSAT simulator, a Launch and Early Orbit Phase(LEOP) operation simulations have been performed. The simulator had been verified through various tests such as functional level test, subsystem test, interface test, system test, and acceptance test. In this paper, simulation results for LEOP operations to verify flight software adapted into simulator, satellite subsystem models and environment models are presented.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.7
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• pp.709-716
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• 2009

Thermal condition according to the operation attitude of a satellite in orbit would be essential to be known because the orbit attitude is a dominant factor to affect satellite thermal design. In this paper, the change in space thermal environment and the thermal effect in thermal design are studied for a low earth orbit satellite according to the yaw motion. The present satellite retains sun-pointing attitude during daylight due to the fixed type solar arrays. And it also moves along the orbit with constant yaw motion in a longitudinal axis so that a star tracker which is a star sensor for satellite's attitude control always looks into the deep space. This attitude is considered in its better visibility to the stars for a successful mission operation. Also, it is required to access the corresponding thermal effects due to the yaw motion. Therefore, we try to verify these by the thermal analysis for the satellite thermal model with the yaw motion.

• Journal of Astronomy and Space Sciences
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• v.27 no.4
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• pp.407-412
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• 2010

Software reusability is one of key factors which impacts cost and schedule on a software development project. It is very crucial also in satellite simulator development since there are many commercial simulator models related to satellite and dynamics. If these models can be used in another simulator platform, great deal of confidence and cost/schedule reduction would be achieved. Simulation model portability (SMP) is maintained by European Space Agency and many models compatible with SMP/simulation model interface (SMI) are available. Korea Aerospace Research Institute (KARI) is developing hardware abstraction layer (HAL) supported satellite simulator to verify on-board software of satellite. From above reasons, KARI wants to port these SMI compatible models to the HAL supported satellite simulator. To port these SMI compatible models to the HAL supported satellite simulator, simulation scheduler is preliminary designed according to the SMI standard.

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.71-75
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• 2006

This paper describes operation plans for satellite communications system (SATCOM) which is consisted of Ka band communication payload, geostationary satellite control system and communication test earth station system for the communication, ocean and meteorological satellite system (COMS). Also this paper describes the communication service and mission plans by each system of the SATCOM, and configurations and functions of the system interface between each system. Especially this paper proposes operational items, functions and their configuration diagrams, touches their operational plans. This paper describes function definitions, configuration diagram and operation plans of the PCS )Payload Control System) for monitor and control of the communication payload and communication service network of the SATCOM.

• Journal of Astronomy and Space Sciences
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• v.37 no.3
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• pp.209-218
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• 2020

This paper describes the initial operations and preliminary results of the Instrument for the study of Stable/Storm-time Space (ISSS) onboard the microsatellite Next Generation Small Satellite-1 (NEXTSat-1), which was launched on December 4, 2018 into a sun-synchronous orbit at an altitude of 575 km with an orbital inclination angle of 97.7°. The spacecraft and the instruments have been working normally, and the results from the observations are in agreement with those from other satellites. Nevertheless, improvement in both the spacecraft/instrument operation and the analysis is suggested to produce more fruitful scientific results from the satellite operations. It is expected that the ISSS observations will become the main mission of the NEXTSat-1 at the end of 2020, when the technological experiments and astronomical observations terminate after two years of operation.