• 제목/요약/키워드: Satellite communications

검색결과 1,750건 처리시간 0.022초

Design of KOMPSAT-2 Simulator

  • Lee, Sanguk;Sungki Cho;Kim, Jaehoon
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2002년도 한국우주과학회보 제11권1호
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    • pp.45.1-45
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    • 2002
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KA-BAND ANTENNA PERFORMANCE ANALYSIS OF COMS SATELLITE

  • Lee Jeom-Hun;Choi Jang-Sup;Lee Seong Pal
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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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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위성 레이저 하향 채널의 대기 영향 분석 (Analysis of Atmospheric Effects of Satellite Laser Down-link Channel)

  • 김원호
    • 한국위성정보통신학회논문지
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    • 제12권4호
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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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    • 제20권4호
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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.

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

  • 오갑근;이상윤;홍완표
    • 한국항행학회논문지
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    • 제13권2호
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    • pp.172-177
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    • 2009
  • 무궁화위성1호가 발사되어 운용 된지 13년이 되었다. 통신위성은 국가기간망의 구축은 물론 인터넷 서비스, 위성방송서비스 등 일반 이용자들에게 멀티미디어 서비스를 제공하는 데 큰 역할과 기여를 하여 오고 있다. 유선초고속인터넷 가입자망의 보급확대와 함께 위성인터넷 가입자의 급속한 감소 등으로 어려운 극면에 처하기도 하였으나 위성통신은 여전히 국가 중요 통신망 구성요소로 자리잡고 있다. 최초의 통신위성이 발사된 후 수개의 상업용통신위성이 발사되어 운용되고 있으나 위성통신서비스의 제도는 제자리 걸음을 하고 있는 실정이다. 본 논문에서는 위성통신서비스 중 소형위성통신기지국에 대한 서비스 제공현황과 제도운용현황을 토대로 문제점을 지적하고 이를 해소하기 위한 정책적대안을 제시한다.

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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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    • 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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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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    • 제19권4호
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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.

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

  • 최가은;송영근
    • 전자통신동향분석
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    • 제39권3호
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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.