• Title/Summary/Keyword: satellite communication system

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System Design of COMS(Communication, Ocean and Meteorological Satellite) Propulsion System (통신해양기상위성 추진시스템 시스템설계)

  • Park Eung-Sik;Han Cho-Young;Chae Jong-Won;Bucknell S.
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2005.11a
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    • pp.426-430
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    • 2005
  • The COMS(Communication, Ocean and Meteorological Satellite) is the first developed three-axis stabilization multi-function satellite on geostationary earth orbit(GEO) in korea, presently scheduled to be launched in 2008. The COMS propulsion system provides the thrust and torque required for the insertion into GEO, attitude and orbit control/adjustment of spacecraft. In this paper, system design of propulsion system, basic functions and design requirement of components are described.

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Development of Web-based Telemedicine using Satellite Internet Communication System (위성인터넷통신을 이용한 Web 기반 원격의료시스템 개발)

  • Hwang, Seon-Cheol
    • Journal of Internet Computing and Services
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    • v.1 no.1
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    • pp.95-104
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    • 2000
  • In general cases, the conventionl Internet connected to a terrestrial network is too slow to transmit large medical images. To overcome this low speed problem of the Internet, we have developed asymmetric satellite data communication system (ASDCS) as a fast satellite Internet communication method. The ASDCS uses a receive-only satellite link for dat delivery and a terrestrial network for control communication. The satellite communication link we implemented showed the very high-speed performance compared to the terrestrial link. Using ASDCS, the satellite Internet communication was 10-30 times faster than the conventional terrestrial Internet link. Also we have developed a Web-based Telemedicine system that can access every permitted server of hospital via the Internet. Java programming techniques were used to make our system and it can access and retrieve medical information and images through only public web browser such as Netscape TM without additional specific tools. To increase the transmitting speed of our Telemedicine system, JPEG method was used. In conclusion, we were able to develop a fast and public Telemedicine system using the proposed ASDCS and Web technology. ASDCS technology increased the speed of the conventional Internet and Web technology extended the scope of use for Telemedicine system from intrahospital to public use.

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Design and Development of an Advanced Real-Time Satellite Simulator

  • Kang, Ja-Young;Kim, Jae-Moung;Chung, Seon-Jong
    • ETRI Journal
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    • v.17 no.3
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    • pp.1-16
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    • 1995
  • An advanced real-time satellite simulator (ARTSS) has been developed to support the ground operations activities of the ETRI satellite control system, such as testing of the system facilities, validation of flight control procedures, verification of satellite commands as well as training of the ground operators. The design of ARTSS is based on the top-down approach and makes use of a modular programming to ensure flexibility in modification and expansion of the system. Graphics-based monitoring and control facilities enhance the satellite simulation environment. The software spacecraft model in ARTSS simulates the characteristics of a geostationary communication satellite using a momentum bias three-axis stabilization control technique. The system can be also interfaced with a hardware payload subsystem such as Ku-band communication transponder to enhance the simulator capability. Therefore, ARTSS is a high fidelity satellite simulation tool that can be used on low-cost desk top computers. In this paper, we describe the design features, the simulation models and the real-time operating functions of the simulator.

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A Mathematical Model for Optimal Communication Scheduling between Multiple Satellites and Multiple Ground Stations (다수의 인공위성-지상국 간 통신 스케줄 최적화 모형)

  • Jeong, Eugine;Kim, Heungseob
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.1
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    • pp.39-49
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    • 2018
  • In the satellite operation phase, a ground station should continuously monitor the status of the satellite and sends out a tasking order, and a satellite should transmit data acquired in the space to the Earth. Therefore, the communication between the satellites and the ground stations is essential. However, a satellite and a ground station located in a specific region on Earth can be connected for a limited time because the satellite is continuously orbiting the Earth, and the communication between satellites and ground stations is only possible on a one-to-one basis. That is, one satellite can not communicate with plural ground stations, and one ground station can communicate with plural satellites concurrently. For such reasons, the efficiency of the communication schedule directly affects the utilization of the satellites. Thus, in this research, considering aforementioned unique situations of spacial communication, the mixed integer programming (MIP) model for the optimal communication planning between multiple satellites and multiple ground stations (MS-MG) is proposed. Furthermore, some numerical experiments are performed to verify and validate the mathematical model. The practical example for them is constructed based on the information of existing satellites and ground stations. The communicable time slots between them were obtained by STK (System Tool Kit), which is a well known professional software for space flight simulation. In the MIP model for the MS-MG problems, the objective function is also considered the minimization of communication cost, and ILOG CPLEX software searches the optimal schedule. Furthermore, it is confirmed that this study can be applied to the location selection of the ground stations.

A Survey for Vulnerability Attack and Defense Method of Satellite-Link Based Communication System

  • Isaac Sim;Jinwoo Jeong;Sangbom Yun;Yunsik Lim;Junghyun Seo
    • International Journal of Internet, Broadcasting and Communication
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    • v.15 no.4
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    • pp.128-133
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    • 2023
  • Satellite based communication is networks in which users in a wide area can access without wired-based ground infrastructure. In particular, the need is emerging due to the recent Ukraine-Russia war. Satellite network systems acquire data that is difficult to observe on Earth as well as communication networks and are also used for research and development, which allows additional data to be produced. However, due to the nature of communication networks existing in outer space, certain vulnerabilities are revealed, and attacks based on them can be exposed. In this paper, we analyze vulnerabilities that may arise due to the nature of satellite communication networks and describes current research, countermeasures, and future research directions.

Network traffic analysis of satellite communication system for hydrologic observation (수문관측용 위성통신시스템의 네트워크 트래픽 분석)

  • Hong, Sungtaek;Park, Jaehyun;Jung, Hoekyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.9
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    • pp.1139-1145
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    • 2019
  • In order to efficiently use defined satellite network resources, it is a priority to understand the performance and usage of the network. In this paper, in order to analyze the operational efficiency and stability of the system in the satellite communication system operated by K-water flood forecast and alarm network, FTP and ping testing and network traffic analysis methods of measuring download and upload speed between central and observational countries were introduced. As a result of measuring the transmission speed by the introduced test method, the effects of TCP accelerators have been improved by 120% upon download from the observational station. Through the performance test and traffic analysis of the satellite hydrologic observation system introduced, environmental improvement and improvement points of the satellite communication system were derived so that the operational efficiency and stability of the communication network could be expected.

Design of Remote Data Collection System using Orbcomm Satellite Communication (오브컴 위성 통신을 이용한 원격지 데이터 수집 시스템 설계)

  • Heo, Min;Jung, Sung-Hun;Mo, Soo-Jong;Lim, Jae-Hong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.122-125
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    • 2005
  • Data collection system is now widely used. This system is divided by embedded system and communication module. And data collection system in the remote area is using Satellite communication. So, data collection system is complicated and expensive. This paper proposes stabilization and cheapness of remote data collection system in dusty. The system can be composed simply through third party Satellite Communication programming of terminal including embedded system. Finally, collected data is transmitted to multi-user through web agent.

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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.

AIS Implementation and Experiment with the Korean Satellite

  • Lee Han-Jin;Lee Changmin;Kang Chang-Gu
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2000.08a
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    • pp.119-123
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    • 2000
  • In this paper, authors introduce about Wide Range Vessel Traffic Service (VTS) system using Automatic Identification System (AIS). In order to develop the prototype of Wide Range VIS system, Korean satellite is used for data communication system for AIS. In this system, ship position obtained by using GPS is reported automatically to VTS center through Korean satellite. By using this system, VTS center can cover more wide area than the case using radar only. And the uncertainty of information is decrease. The results of test show the good possibility of VTS using satellite and AIS.

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