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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/5086

    Title: 梯度漂移不規則體之準週期性移動的研究
    Authors: 陳建智;Jian-Jr Chen
    Contributors: 太空科學研究所
    Keywords: 電離層;不規則體;VHF雷達;準週期性回波;ionosphere;irregularity;VHF radar;quasi-periodic echo
    Date: 2000-07-05
    Issue Date: 2009-09-22 09:44:48 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 中緯度地區電離層散塊E層的不規則體主要是由梯度漂移不穩定的物理機制所引起,由頻譜上來看是屬於型態二的不規則體。 本研究是利用位於中緯度地區的中壢特高頻雷達,從1999年7月到2000年2月,以52MHz的發射頻率觀測3公尺左右結構的不規則體,針對所觀測的資料做分析,另外也分析1996年所觀測的資料,分析的內容包括:(1)利用雷達干涉法研究不規則體於空間中的漂移運動,(2)系統相位差的估計,(3)頻寬與平均都卜勒頻移的關係。另外亦提出以散塊漂移的理論來說明,在回波功率之高度-時間-強度(RTI)圖中呈線紋結構的準週期性回波(QP Echo),是由場沿不規則體準週期性的漂入雷達體積所造成的現象。 The sporadic E irregularities associated with typeII radar spectra are mainly caused by gradient drift instability at mid-latitude ionospheric region. Employing the Chung-Li 52MHz radar, the observations of meter-scale irregularities were carried out from July, 1999 to February, 2000. In addition, the analysis of data taken in 1996 was also included in this study. The analysis include: (1) using radar interferometer to research the drift motions of irregularities (2) the estimation of system phase difference (3) relationships between spectral widths and mean doppler shifts. Futhermore, propose a possible mechanism to explain the quasi-periodic(QP) echoes that present the striated structures in the RTI plot, which is the phenomenon caused by field aligned irregularities drift into radar volume quasi-periodically.
    Appears in Collections:[太空科學研究所 ] 博碩士論文

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