• Title/Summary/Keyword: communications satellite

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KA-BAND ANTENNA PERFORMANCE ANALYSIS OF COMS SATELLITE

  • Lee Jeom-Hun;Choi Jang-Sup;Lee Seong Pal
    • Bulletin of the Korean Space Science Society
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    • 2004.10b
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    • pp.316-320
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    • 2004
  • This paper describes Ka-band antenna performance analysis of COMS satellite. The key parameters of the antenna system are optimal antenna diameter, feed horn type and horn size, F/D, and the coordinate of offset horns. The paper deals with the method to determine design core parameters of optimal antenna diameter, feed horn type and horn size, F/D, and the coordinate of offset horns, and the performances of design result.

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Analysis of Atmospheric Effects of Satellite Laser Down-link Channel (위성 레이저 하향 채널의 대기 영향 분석)

  • Kim, Won-Ho
    • Journal of Satellite, Information and Communications
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    • v.12 no.4
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    • pp.166-169
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    • 2017
  • This paper describes atmospheric phenomena and effects for satellite-to-ground laser communication channel. Satellite laser communication has advantages such as very high bandwidth, inherent security, robustness to electromagnetic interference, unlicensed frequency band. However, satellite laser communication is affected by various factors. Transmission quality is degraded by factors as system loss, geometric loss, misalignment loss, atmospheric loss. Atmospheric loss is major factor of performance degradation. In this paper, the atmospheric phenomena such as absorption, scattering and turbulence are discussed and analyzed for developing satellite laser channel model and laser transmission scheme robust to atmospheric phenomena.

COMMUNICATIONS SATELLITE SYSTEM BY USING MOON ORBIT SATELLITE CONSTELLATION

  • Lee, Sang-Uk;Kim, Jae-Hoon;Lee, Seong-Pal
    • Journal of Astronomy and Space Sciences
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    • v.20 no.4
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    • pp.313-318
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    • 2003
  • A communications satellite system placed in three-Lagrange points, $L_3$, $L_4$ and $L_5$, of the restricted three-body problem in Earth-Moon system is proposed in this paper. LEO satellite constellation has been another choice of communications system. The proposed system which is alternatives of limited geostationary orbit resources, has some weak points such as long distance from the Earth, relatively expensive launch cost, long delay time, more required power, and so on. It has good points like less efforts (fuel) for station keeping, less eclipses, etc. This system has limitations for applications to provide commercial services but it is still some attractive points.

A study on policy of VSAT (Very Small Aperture Terminal) license system (소형위성지구국(VSAT)허가 제도에 관한 정책 연구)

  • Oh, Gab-Kuen;Lee, Sang-Yun;Hong, Wan-Pyo
    • Journal of Advanced Navigation Technology
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    • v.13 no.2
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    • pp.172-177
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    • 2009
  • Mugunghwa Satellite N0.1 is fired after operation was 13 years. The establishment of communication satellites, as well as Internet service backbone network the country, including satellite broadcasting services to provide multimedia services to general users and contribute to have a big role. High-speed Internet Access Network was expanded and satellite Internet subscribers Access Network rapidly decreasing, but it also a difficult situation, satellite communications network is still important as a component is located. Launched the first communication satellite to be launched and operated several commercial communications satellite, but satellite communications services and the pace of the system is in place. In this paper VSAT, satellite communications service to provide a service based on the status and problems of the status of operating system and will present alternative policies to solve.

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Automated command generation for satellite control

  • Mo, Hee-Sook;Kim, Jae-Hoon;Lee, Ho-Jin
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.380-383
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    • 1995
  • Since the generation and transmission of telecommand in satellite monitoring and control system depend on the decisions of operators, it is possible that operators with different levels of knowledge may generate different telecommands in the same situation. Because of this reason, automation technology of satellite operation is being researched and developed to minimize the decision error due to the operator's lack of experience. This paper suggests a method of automated satellite control, which generates telecommands automatically using the knowledge of satellite subsystem engineers or specialists for the ground system. This method provides safe satellite operation and expansion of satellite life time by automatic generation of the telecommands, so that the operator's interrupt is minimized which provides the efficient satellite control.

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3D DISPLAY OF SPACECRAFT DYNAMICS USING REAL TELEMETRY

  • Lee, Sang-Uk;Cho, Sung-Ki;Kim, Jae-Hoon
    • Journal of Astronomy and Space Sciences
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    • v.19 no.4
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    • pp.403-408
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    • 2002
  • 3D display of spacecraft motion by using telemetry data received from satellite in real-time is described. Telemetry data are converted to the appropriate form for 3-D display by the real-time preprocessor. Stored playback telemetry data also can be processed for the display. 3D display of spacecraft motion by using real telemetry data provides intuitive comprehension of spacecraft dynamics.

Low Earth Orbit Satellite Communications, Applications and Major Operators' Service Deployments (저궤도 위성통신의 활용과 주요 사업자의 서비스 전개 현황)

  • G.E. Choi;Y.K. Song
    • Electronics and Telecommunications Trends
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    • v.39 no.3
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    • pp.36-47
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    • 2024
  • Low Earth Orbit (LEO) satellite communications has become a crucial technology for next-generation communication networks owing to its hyperconnectivity capabilities. We examine the progress and application areas of LEO satellite communication services. The LEO satellite communication industry has transitioned from being predominantly driven by governments and institutions to being led by the private sector, following the trajectory of the NewSpace movement. Leading corporations such as SpaceX Starlink and Eutelsat OneWeb are deploying LEO satellite networks to offer internet services, while Telesat is preparing to establish its satellite communication network. LEO satellite communications is expected to have a major impact on various sectors of society, particularly for upcoming sixth-generation services. Therefore, the South Korean government must promptly formulate policy support strategies aimed at invigorating the LEO satellite communication industry. This can be achieved through initiatives such as bolstering research and development and extending corporate assistance.