• Title/Summary/Keyword: COMS communication

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PRELIMINARY COMS AOCS DESIGN FOR OPTIMAL OPTICAL PAYLOADS OPERATIONS

  • Park, Young-Woong;Park, Keun-Joo;Lee, Hun-Hei;Ju, Gwang-Hyuk;Park, Bong-Kyu
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.290-293
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    • 2006
  • COMS (Communication, Ocean and Meteorological Satellite) shall be operated with two remote sensing payloads, MI (Meteorological Imager) and GOCI (Geostationary Ocean Color Imager). Since both payloads have rotating mechanisms, the dynamic coupling between two payloads is very important considering the pointing stability during GOCI operation. In addition, COMS adopts a single solar wing to improve the image quality, which leads to the unbalanced solar pressure torque in COMS. As a result, the off-loading of the wheel momentum needs to be performed regularly (2 times per day). Since the frequent off-loading could affect MI/GOCI imaging performance, another suboptimal off-loading time needs to be considered to meet the AOCS design requirements of COMS while having margin enough in the number of thruster actuations. In this paper, preliminary analysis results on the pointing stability and the wheel off-loading time selection with respect to MI/GOCI operations are presented.

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A Study on Establishment of Appropriate Observation Time for Estimation of Daily Land Surface Temperature using COMS in Korea Peninsula (천리안 위성 자료를 활용한 한반도의 일별 지면 온도 산정을 위한 적정 관측시간 설정 연구)

  • Lee, Yong Gwan;Jung, Chung Gil;Lee, Ji Wan;Kim, Seong Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.58 no.4
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    • pp.37-46
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    • 2016
  • This study is to estimate COMS (Communication, Ocean and Meteorological Satellite) daily land surface temperature (LST) of Korea Peninsula from 15 minutes interval COMS LST (COMS LST-15) satellite data. Using daily observed LST data of Automated Agriculture Observing System (AAOS) 11 stations from January 2013 to May 2015, the COMS daily LST was compared and validated. For the representative time for daily mean LST value from COMS LST-15, the time of 23 : 45 and 0:00 showed minimum deviations with AAOS daily LST. The time zone from 23 : 45 to 1:15 and from 7 : 30 to 9 : 45 showed high determination coefficient (R2) of 0.88 and 0.90 respectively. The daily COMS LST by averaging COMS LST-15 of the day showed R2 of 0.83. From the 5 cases of results, the COMS daily LST could be extracted from the average LST by using 15 minutes data from 7 : 30 to 9 : 45.

First Bipropellant Propulsion System for Spacecraft in Korea

  • Han, Cho-Young;Chae, Jong-Won;Park, Eung-Sik;Baek, Myung-Jin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.03a
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    • pp.307-310
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    • 2008
  • In the framework of COMS(Communication, Ocean and Meteorological Satellite) programme, the first bipropellant propulsion system for GEO satellite has been developed successfully. So far Korea has its own experience of development of a monopropellant propulsion system for LEO satellites, i.e., KOMPSAT's. Other types of propulsion systems for a satellite, such as cold gas and electric propulsion etc., are being developed somewhere in Korea, however they are not commercialised yet, apart from those two systems aforementioned. This paper mainly focused on the design of the Chemical Propulsion System(CPS) for the COMS, joint scientific and communications satellite. It includes descriptions of the general system design and a summary of the supporting analysis performed to verify suitability for space flight. Essentially it provides an overview and guide to the various engineering rationale generated in support of the COMS CPS design activities. The manufacture and subsequent testing of COMS CPS are briefly discussed. Feasibility of COMS CPS to an interplanetary mission is proposed as well.

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COMS System Bus Design and Analysis using MIL-STD-1553B (MIL-STD-1553B 버스를 이용한 통신해양기상위성의 시스템 버스 설계 및 분석)

  • Cho, Young-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.7
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    • pp.1285-1289
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    • 2008
  • In this paper, we design COMS system bus that the 1553 Data Bus is able to link all the units of the satellite managed by the SCU using one Prime Data Bus and on Redundant Data Bus. Also we analyze MIL-STD-1553B bus load and relevant exchange memory budgets in system bus of the COMS satellite. This data is used in the satellite mission and software design by system engineer.

Study on Solar Constraint in the Operation of COMS Meteorological Imager

  • Cho Young-Min
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.382-385
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    • 2004
  • Communication Ocean Meteorological Satellite (COMS) for the hybrid mission of meteorological observation, ocean monitoring, and telecommunication service is planned to be launched onto Geostationary Earth Orbit in 2008 according to the Korea national space program. A feasibility study on the solar constraint in the operation of the COMS meteorological imager (MI) is performed using the GOES imager hardware operation characteristics. The Earth observation areas of the MI are introduced and the observation time of the MI observation area is calculated. The sun light can enter into the MI optical system around the local midnight and impinge on the performance of the MI. The solar eclipse viewed from the satellite occurs near local midnight around the equinox. This study discusses the restriction of imaging operation time that should be considered in order to avoid the solar intrusion about local midnight and to keep acceptable image quality for the MI observation areas. This study could be useful to build the operation concept of the MI during the development of the MI.

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Scheduling North-South Mirror Motion between Two Consecutive Meteorological Images of COMS

  • Lee, Soo-Jeon;Jung, Won-Chan;Kim, Jae-Hoon
    • Journal of Satellite, Information and Communications
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    • v.3 no.2
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    • pp.26-31
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    • 2008
  • As a multi-mission GEO satellite, Communication, Ocean, and Meteorological Satellite (COMS) is scheduled to be launched in the year 2009. COMS has three different payloads: Ka-band communication payload, Geostationary Ocean Color Imager (GOCI) and Meteorological Imager (MI). Among the three payloads, MI and GOCI have several conflict relationships; one of them is that if MI mirror moves vertically larger than 4 Line Of Sight (LOS) angle while GOCI is imaging, image quality of GOCI becomes degraded. In this paper, MI scheduling algorithm to prevent GOCI's image quality degradation will be presented.

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OVERVIEW OF COMS GROUND SYSTEM AT METEOROLOGICAL SATELLITE CENTER OF KMA

  • Lee, Hyun-Kyoung;Lee, Bong-Ju;Lee, Yong-Sang;Shim, Jae-Myun;Suh, Ae-Sook;Kim, Hong-Sic;Je, Chang-Eon
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.159-162
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    • 2006
  • This paper describes the ground system for COMS (Communication, Ocean, and Meteorological Satellite), the first Korean multi-purposed geostationary satellite, at MSC (Meteorological Satellite Center) in Korea. The overview of COMS MI (Meteorological Imager) will be introduced as well. KMA would implement mission planning for COMS MI operation and receive, process, interpret, disseminate, and archive MI data operationally for domestic and foreign user groups. Major missions of COMS MI are mitigation of natural hazard such as typhoon, dust storm, and heavy rain, and short-term warning of severe weather to protect human health and commerce. Moreover, research of climate variability and long-term changes will be supported. In accordance with those missions, the concept and design of COMPASS (COMS operation and meteorological products application service system), the ground system for COMS MI in MSC, have been setting up since 2004. Currently, COMPASS design is being progressed and will have finished the end of 2006. The development of COMPASS has three phases: first phase is development of fundamental COMPASS components in 2007, second phase is to integrate and test all of the COMPASS components in 2008, and the last phase is to operate COMPASS after COMS In-Orbit Tests in 2009.

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A STUDY OF ANALYTIC METHOD AND NUMERICAL SIMULATION FOR CONCEPTUAL DESIGN OF BUS RADIATOR AND HEATER POWER OF COMS (COMMUNICATION, OCEAN AND METEOROLOGICAL SATELLITE) (통신해양기상위성 본체 방열판 및 히터 개념설계를 위한 해석적 방법 및 수치모사 연구)

  • Kim Jung-Hoon;Jun Hyung Yoll;Yang Koon-Ho
    • Journal of computational fluids engineering
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    • v.10 no.3 s.30
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    • pp.63-69
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    • 2005
  • The COMS, the first meteorological geostationary satellite in Korea, is under development by KARI. The radiator size and the heater power for the thermal control of COMS are calculated using an analytic method. The total radiator area of $4.85\;m^2$ and the total heater power of 794.77 W are determined at a conceptual design of COMS. The commercial software, SINDA and TRASYS, are utilized in order to compare and verify the analytic results. The results of on-orbit numerical simulation of cold and hot cases show that the radiator size and heater power obtained from the analytic method are appropriate to maintain COMS equipments within required temperature ranges.

A STUDY ON THE EAST/WEST STATION KEEPING PLANNING CONSIDERING WHEEL OFF-LOADING

  • Lee, Sang-Cherl;Park, Bong-Kyu;Kim, Bang-Yeop;Ju, Gwang-Hyeok;Yang, Koon-Ho
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.263-266
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    • 2006
  • Now, on the developing COMS(Communication, Ocean and Meteorological Satellite) has solar panel on the South panel only. Therefore, the wheel off-loading has to be performed periodically to reduce a induced momentum energy by a asymmetric solar panel. One of two East/West station keeping maneuver to correct simultaneously longitude and eccentricity, orbit corrections may be performed during one of the two wheel off-loading manoeuvres per day to get enough observation time for meteorological and ocean sensor. In this paper, we applied a linearized orbit maneuver equation to acquire maneuver time and delta-V. Nonlinear simulation for the station keeping is performed and compared with general station keeping strategy for fuel reduction.

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