• Journal of information and communication convergence engineering
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• v.3 no.3
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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.

• Proceedings of the IEEK Conference
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• 2004.06a
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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

• Proceedings of the KSRS Conference
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• 2004.10a
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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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• v.5 no.1
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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.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.10
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• pp.134-141
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• 2004

This paper addresses development of the conceptual design program of satellite communication system. A database for more than 200 small satellites of LEO which are between 10kg and 200kg was constructed to conduct a sequential process of conceptual design. General parameters based on the database were derived to be able to use for initial design of satellite communication system. The general conceptual design process developed and programed in this work is applicable to micro-class small satellites without regard to mission types. This conceptual design algorithm is consisted of five sequential steps, in which various parameters are defined every phase. These parameters are utilized for conceptual design through database analysis. The validity of an entire design algorithm has been demonstrated via program simulation.