• Journal of information and communication convergence engineering
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• 제3권3호
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• pp.146-151
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• 2005

This paper represents an attempt to bring together and analyses the measurement data measured by the Satellite Signal Monitoring Center in Korea and the Korea Meteorological Administration/Korea Meteorological Research Institute in close cooperation with this study team. This paper presents the signal characteristic of GEO satellite operating in frequency range 1 to 20GHz associated with Asian Sand Dust (the so-called Yellow Sand Dust). The downlink signal power (dBm) for L-, S-, C-, Ku-, and Ka-band frequencies from GEO satellites were measured in a clear weather and in Asian Sand Dust weather by the Satellite Signal Monitoring Center. The measured signal power(dBm) were compared to the total number concentration and size distribution of Sand Dust that were measured by the Korea Meteorological Administration/Korea Meteorological Research Institute and the possible correlation between these sets data were analyzed. The results demonstrate that the downlink signal level (dBm) of GEO satellite is attenuated by Asian Sand Dust. Hitherto, merger information has been reported as to the influence of sand dust on satellite communications operating in regions affected by sand dust.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(1)
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• pp.87-90
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• 2004

This paper proposes 4-STTD(4${\times}$l) technique for the shake of application of W-CDMA which expand Alamouti STTD(2${\times}$l) technique. As the result of analyzing 4-STTD(4${\times}$l) technique proposed in this paper, we can see improvement of quality by approximately 2.2 dB rather than Alamouti STTD(2${\times}$l) technique

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.467-470
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• 2004

In early 2004, KARI developed 5ft S-Band TT&C antenna for especially KOMPSAT-2 operation in LEOP phase. This paper shows system features of 5ft S-Band antenna and its test result with KOMPSAT-l. Tracking test, command uplink test and telemetry downlink test were performed. Through tests, 5ft antenna was verified to be operational in uplink and downlink with KOMPSAT series. Due to its inherent wide 3dB beam-width of about 7deg at S-Band, this antenna system can be used very effectively even though orbital information is less accurate like LEOP and spacecraft safe mode.

• International Journal of Aeronautical and Space Sciences
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• 제5권1호
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• pp.6-18
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• 2004

This paper addresses the development and design of the HAUSAT-l (Hankuk Aviation University SA'Tellite-D communication subsystem, which is a next generation picosatellite, developed by SSRL (Space System Research Lab.) of Hankuk Aviation University. The communication subsystem generally consumes the majority of power and volume for picosatellites, and thus its design is critical to the overall satellite and mission plans. The HAUSAT-l designs are implemented by using the 145.84 MHz for uplink and 435.84 MHz for downlink frequency bands. The simulation and test results of the homemade radio and the TNC (Terminal Node Controller) integrated on the HAUSAT - I , a picosatellite scheduled to launch on September 2004 by Russian launch vehicle "Dnepr", are presented for EM, QM and FM, respectively.

• 한국항공우주학회지
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• 제32권10호
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• pp.134-141
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• 2004

본 논문은 위성 통신시스템의 개념 설계를 위한 프로그램 개발과 설계 과정의 분석 결과를 보여준다. 이를 위해 10kg에서 200Kg 사이의 200여개 저궤도 소형위성을 대상으로 데이터베이스를 구축하였고, 이를 바탕으로 위성 통신시스템 초기 설계 시 필요한 파라미터들의 일반적인 값을 도출하여 적용하였다. 위성의 임무에 상관없이 일반적인 위성 통신 시스템의 개념 설계와 일련의 과정을 일반화한 프로그램을 개발하였다. 본 논문에서는 일반적인 초기 통신시스템 설계과정을 프로그램으로 구현하기 위해 각각의 과정을 구분하고 과정마다 필요한 파라미터들을 정의하였다. 또한 데이터베이스 분석을 통해 파라미터가 개념 설계에 적용되는 과정을 살펴보고 이를 프로그램으로 구현하여 시뮬레이션을 통해 전체 알고리즘에 대한 타당성을 증명하였다.