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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/5117

    Title: 低軌道Ka波段人造衛星標識訊號特性之研究
    Authors: 葉日欣;Jih-Hsin Yeh
    Contributors: 太空科學研究所
    Keywords: 波束寬;閃爍;Ka 波段;Ka Band;Scintillation;Bandwidth
    Date: 2002-06-10
    Issue Date: 2009-09-22 09:45:22 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 本論文利用中華衛星一號通訊實驗酬載來探討Ka波段標識訊號(Beacon Signal)的特性。利用機動式地面接收站(Transportable Ground Terminal,TGT)及固定式地面站(Remote Ground Terminal RGT),在2000年到2001年間所接收之標識訊號來研究接收功率的變化,同時,對大氣閃爍效應(scintillation)作初步分析。結果發現接收之標識訊號功率有隨時間下降的趨勢。而在閃爍事件的觀研究中,發現頻譜大致符合理論值-8/3之斜率。此外,在探討天線波束寬對預測衛星訊號的影響中,發現波束寬越大,預測訊號所受到的影響越明顯。另外,在大氣衰減量(t0)與地面大氣折射指數(Ns)的分析中,得到了兩者的關係式t0=-1.1713+0.0047Ns,而由TGT和RGT上微波輻射儀(Radiometer)與地面輻射儀的比較中,發現TGT和RGT上的輻射儀系統並不穩定。 From the signals transmitted by the experimental communication payload (ECP) on the ROCSAT-1, the study analyzed Beacon Signal with frequency of Ka-band. We discussed the change of the received power by analyzing the beacon signal from the Transportable Ground Terminal and the Remote Ground Terminal during 2000 to 2001. Also, we made some analysis of Preliminary Results of the scintillation. The data indicated that the power declined with time and in the observation of the scintillation, we discovered the slope of the spectrum matched the ideal number of –8/3.Moreover, we found that the wider the bandwidth, the stronger the predicted signal would be affected. Besides, we drew a conclusion of t0 = -1.1713 + 0.0047 Ns on the relation between the attenuation of atmosphere and the atmospheric refractive index. In the comparison of TGT and RGT to 19.5 GHz Radiometers, we found the instability of the TGT and RGT system.
    Appears in Collections:[太空科學研究所 ] 博碩士論文

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