• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.30-31
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• 2003

본 연구에서는 통신해양기상위성의 기상관측 탑재체인 기상 영상기(Imager)의 개발을 위해 정지궤도 위성의 분광 채널별 Modulation Transfer Function (MTF) 특성을 현재 운영 및 개발 중인 위성 영상기 기술 범위에서 분석하였다. 통신해양기상위성은 국내 최초로 통신, 해양, 기상 3분야 복합 임무를 수행하는 정지제도 위성으로 2003년부터 개발되어 2008년 발사 예정이다. (중략)

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.179.1-179.1
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• 2012

정지궤도 복합위성 2호는 현재 기상 및 해양관련 관측임무를 수행중인 천리안위성의 임무승계를 위해 현재 개발이 진행 중이다. 천리안위성에 비해 수명이 확대되고, 임무 탑재체의 중량도 증가하여 추진제량의 대폭 증가가 필요한 것으로 분석되고 있다. 이로 인해 추진제 탱크의 확장이 불가피하여 현재 가용한 탱크를 기반으로 구조체 설계에 대한 비교 연구가 수행되었다. 정지궤도위성의 추진제 탱크 수용은 크게 측면 고정식 구형 탱크의 수직 배치방식과 극 고정식 실런더형 탱크의 수평 배치방식으로 구분된다. 추진제량 확대에 따라 두가지 방식 모두 구조체 내부에 충분한 강성확보와 하중전달을 목적으로 튜브형 구조물이 적용되며, 이를 토대로 구조체 설계가 이루어 진다. 본 논문에서는 이러한 추진계 탱크 수용 방식을 기반으로 정지궤도 복합위성에 적용될 구조체 설계 개념을 제시하고, 비교 연구를 통해 각 방식이 갖는 구조체 설계의 장단점을 기술하고자 한다.

• Aerospace Engineering and Technology
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• v.12 no.2
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• pp.30-39
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• 2013

In this study, calibration processes and methods of evaluating the radiometric quality of satellite images from the meteorological payload on the GEO-KOMPSAT-2A were described. MTF(Modulation Transfer Function), SNR(Signal-To-Noise Ratio), NEdT(Noise Equivalent Delta Temperature), and Dynamic Range, which are the major parameters for assessment of data radiometric quality of space-borne visible and infrared sensors, are focused. Key process of the quality check of the satellite data is the comparing the image radiometric performance parameters during the In-Oribit Test with those acquired from the ground tests. Validation plan of the image quality of the GEO-KOMPSAT-2A Meteorological Imager is addressed based on the analyses results of COMS MI data during the COMS In-Orbit Test period

• Aerospace Engineering and Technology
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• v.8 no.2
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• pp.68-74
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• 2009

Infra-red earth sensors(IRES) are accommodated in a geostationary multi-functional satellite, which includes optical payloads for observing the earth, to provide pointing reference for the payloads. Even the slight pointing difference between the IRES and the payloads is so critical from the geostationary orbit that can degrade their imaging performance. Therefore, a dedicated support structure is required to guarantee the stability during the flight operation. This paper shows the design justification for the IRES support structure employed in the Communication, Ocean and Meteorological Satellite(COMS). It intends to give an overall design presentation and to justify that this design is compatible with all the requirements in terms of stiffness and strength as well as the stability.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.345-347
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• 2015

인공위성은 다양한 센서장치, 구동장치, 전자장치들로 구성되어 있으며, 위성을 제어하는 컴퓨터 장치는 이들 장치들과 다양한 종류의 통신 버스로 연결되어있다. 정의된 프로토콜에 따라 명령을 전송하고 장치들의 상태 정보를 수집하여 위성을 운영한다. 위성에서 많이 사용되는 대부분의 상용 센서나 구동장치들은 표준화된 버스 (ex, 1553B, CAN, UART, etc ...) 인터페이스를 지원한다. 그러나 위성의 임무나 설계에 맞게 특수하게 제작된 장치의 경우는 범용의 버스보다는 용도에 적합한 프로토콜이 설계되고 제작된다. 본 논문에서는 2018년 발사 예정인 정지궤도복합위성 컴퓨터 장치 (GMU) 내의 프로세스 모듈과 시스템의 이상상태를 감지하여 GMU의 운용 모드 및 형상의 변경을 담당하는 MRE 모듈사이의 통신을 담당하는 IMGL 설계를 소개하고 IMGL 운영을 담당하는 소프트웨어 설계 및 구현 내용을 기술한다.

• Aerospace Engineering and Technology
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• v.10 no.2
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• pp.65-73
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• 2011

After launch, in order to inject the geostationary satellite into its operational orbit, the perigee altitude are forced to be raised to geostationary altitude by firing onboard LAE(Liquid Apogee Engine) at apogee of the transfer orbit. In this process, the LAE burn is divided into three or four separated burns in order to control the orbit very precisely by giving feedback the determined orbit informations and to inject the satellite in predefined longitude. This paper proposes an algorithm to determine LAE firing time slots and ${\Delta}V$ vectors under assumption of impulsive LAE burning, and additionally, a method to compensate errors induced by continuous burning. And computer simulations have been performed to validate proposed algorithms.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.110-115
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• 2012

Satellite structure should be designed to accommodate and support safely the payload and equipments necessary for its own missions and to secure satellite and payloads from severe launch environments. The launch environments imposed on satellites are quasi-static accelerations, aerodynamic loads, acoustic loads and shock loads. Currently KARI(Korea Aerospace Research Institute) is developing Geo-KOMPSAT-2(Geostationary Earth Orbit KOrea Multi-Purpose Satellite) with technologies which were acquired during COMS(Communication, Ocean and Meteorological Satellite) development. As compared to COMS Geo-KOMPSAT-2 requires more propellant due to mass increase of Advanced Meteorological Payload with high resolution and increase of miss life, it is difficult to apply the design concept of COMS to Geo-KOMPSAT-2. This paper deals with conceptual design of Structural Subsystem for Geo-KOMPSAT-2.

• Aerospace Engineering and Technology
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• v.2 no.2
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• pp.89-95
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• 2003

In this study, the technical characteristics of geosynchronous multi-mission satellites are investigated, compared to communication satellites. Geosynchronous meteorological satellites, whose imaging data is normally shared with the international society, have large coverage for monitoring and data service. Also the higher pointing accuracy is requested to keep the spatial resolution of 1-4km, compared to those of communication satellites. Cryogenic thermal control is needed for the better performance of IR sensors and the contamination protection of optical parts should be considered. On the other hands, for the successful development of the multi-mission satellite COMS, which will be launched in 2008, the special features of attitude control, electrical power, thermal control and mechanism are investigated.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.99-107
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• 2008

The COMS is a kind of geostationary multi-functional satellites with three different mission objectives. Two of them aim at earth observation and the COMS has two optical payloads according to those missions. The payloads are composed of a meteo imager and an ocean color imager, and their inherent characteristics require optimal interface design for their performance to be concurrently achieved. Therefore, various kinds of constraints are considered in their component accommodation on the COMS platform. This paper shows a general overview of the optical payload accommodation design and describes the design consideration to achieve the optimized performance from thermal and mechanical point of view.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.7
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• pp.551-556
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• 2018

A lot of hardwares are allocated on the satellite to perform the attitude control. Sun sensor is very important hardware to acquire the initial attitude after separation from launcher and to maintain the safety attitude from the satellite anomaly operation. So the allocation of the sun sensor to acquire the field of view and the attitude control design using it, are critical work in the beginning of development. Number of Sun sensor for GEO-KOMPSAT2 is reduced with respect to COMS due to star tracker usage. The additional sun sensor using COMS heritage is considered. In this paper, it is described the analysis and the results on the method for the safety improvement which is to enlarge the field of view and to consider the harness connection of P/R-side of the sun sensor.