![]() |
|
以作者查詢圖書館館藏 、以作者查詢臺灣博碩士 、以作者查詢全國書目 、勘誤回報 、線上人數:29 、訪客IP:18.190.207.235
姓名 邵宜群(Yi-Chiun Shau) 查詢紙本館藏 畢業系所 太空科學研究所 論文名稱 植被遮蔽效應對Ka波段電波衰減影響之探討
(Measurements of attenuation of vegetation effect at Ka-band.)相關論文 檔案 [Endnote RIS 格式]
[Bibtex 格式]
[相關文章]
[文章引用]
[完整記錄]
[館藏目錄]
[檢視]
[下載]
- 本電子論文使用權限為同意立即開放。
- 已達開放權限電子全文僅授權使用者為學術研究之目的,進行個人非營利性質之檢索、閱讀、列印。
- 請遵守中華民國著作權法之相關規定,切勿任意重製、散佈、改作、轉貼、播送,以免觸法。
摘要(中) 隨著無線多媒體網際網路應用的日益頻繁,地面微波通訊的應用上日趨重要,由於頻譜之擁擠,世界各國均傾向採用Ka(26~40GHz)波段。不過此一波段信號在地表大氣通道傳播時,容易受到自然環境因素影響,其中植被遮蔽造成的信號衰減情況甚為嚴重,所以本文將針對植被遮蔽的效應進行討論。
在植被遮蔽效應實驗,以闊葉榕樹進行量測訊號穿透的功率衰減和功率機率分佈。當植被遮蔽效應時,藉由不同極化情形下所能得知入射功率、輸出功率和植被遮蔽路徑長度之關係。經由實驗後發現在不同發射、接收極化方向情況下所得到的接收功率會有所差異,其植被消散係數也會有所差異,實驗結果中得知在垂直發射、垂直接收情況下訊號的衰減和推算出植被之消散係數為26.80dB和4.85dB/m。水平發射、水平接收情況為29.44dB和5.10dB/m。而垂直發射、水平接收情況為18.85dB和4.70dB/m。水平發射、垂直接收情況為20.67dB和4.82dB/m。摘要(英) With more and more applications in the wireless internet multimedia, the importance of terrestrial microwave communication should be studied and investigated. However, a lot of people tend to apply the frequency in Ka-band (26-40GHz) for the lack of the useful spectra. But the region of Ka-band is sensitive to be influenced by the environment, when it transferred in the atmosphere, especially for the attenuation by the vegetations. In this study, we will discuss some effects of that.
In the experiment of vegetations effect, the experiment is operated in a transmit-through mode. And the kind of tree is banyan which is used to measure the attenuation and made the probability distribution pass through it. And we show the expression relating the power of the received power to the incident power and the thickness of the random-medium layer of different polarization under vegetations effect. It showed that the power and the extinction coefficient change due to the different polarization of transmit and receive modules. The attenuation of receive power and the extinction coefficient for both horizontally polarized form are 26.80 dB and 4.84 dB/m. The attenuation of receive power and the extinction coefficient for both vertically polarized form are 29.44 dB and 5.09 dB/m. The attenuation of receive power and the extinction coefficient for horizontally and vertically polarized form are 18.85 dB and 4.58 dB/m. The attenuation of receive power and the extinction coefficient for vertically and horizontally polarized form are 20.67 dB and 4.79 dB/m.關鍵字(中) ★ 植被效應
★ 訊號衰減
★ 電磁波量測關鍵字(英) ★ vegetation effect
★ attenuation
★ 28 GHz
★ extinction coefficient論文目次 摘要: i
Abstract: ii
第一章 緒論 1
1.1 研究目的 1
1.2 文獻回顧 3
1.3 章節介紹 4
第二章 電磁波於大氣中的傳播 5
2.1電磁波的傳播機制 5
2.1.1 吸收(Absorption) 5
2.1.2 折射(Refraction) 5
2.1.3 散射(Scattering),反射(Reflection) 6
2.1.4 多重路徑(Milti-path) 7
2.1.5 衰減(Attenuation) 8
2.2視距傳播(Line of Sight Propagation ) 9
2.3地面微波波段電磁波於大氣中傳播的環境機制 9
2.3.1 氣體的吸收(Gaseous Absorption) 9
2.3.2去極化效應(Depolarization Effect) 11
2.3.3地面多重路徑效應(Multi-path Effect) 11
第三章 實驗量測系統設置介紹 12
3.1信號發射端 13
3.2信號接收端 17
3.3資料儲存及控制軟體 21
第四章 植被遮蔽效應實驗 24
4.1植被遮蔽效應之探討 24
4.2實驗設備 25
4.3實驗量測系統參數 26
4.4實驗設備架設 27
4.5實驗樹種與樹葉 29
4.6實驗誤差來源 31
4.6.1距離 31
4.6.2天線場型 31
4.6.3大氣介質 32
4.6.4硬體設備 32
4.6.5人為誤差 32
4.7實驗步驟 33
第五章 植被遮蔽效應實驗結果與討論 34
5.1功率衰減 34
5.1.1水平發射、水平接收(HH) 34
5.1.2垂直發射、垂直接收(VV) 38
5.1.3水平發射、垂直接收(HV) 42
5.1.4垂直發射、水平接收(VH) 43
5.2消散係數 47
5.2.1水平發射、水平接收(HH) 49
5.2.2垂直發射、垂直接收(VV) 50
5.2.3水平發射、垂直接收(HV) 51
5.2.4垂直發射、水平接收(VH) 52
5.3接收功率之分布情形 53
5.3.1水平發射、水平接收(HH) 53
5.3.2垂直發射、垂直接收(VV) 60
5.3.3水平發射、垂直接收(HV) 67
5.3.4垂直發射、水平接收(VH) 70
第六章 結論與未來工作 74
6.1結論 74
6.2未來工作 76
References: 77參考文獻 [1] S. T. Wu, “Preliminary Report on Measurement of Forest Canopies with C Band Radar Scatterometer at NASA/NSLT,” IEEE Trans Geosci. Remote Sensing, vol. GE-24, pp. 894-899, 1986.
[2] H. Hirosawa, Y. Matsuzaka, and O. Kobayashi, “Measurement of Microwave Backscatter from a Cypress With and Without Leaves,” IEEE Trans. Geosci. Remote Sensing, vol. 27, no. 6, pp.698-701, 1989.
[3]Felix K. Schwering,Edmond J. Violette and Richard H. Espeland,”Millimeter-Wave Propagation in Vegetation: Experiments and Theory,”IEEE Trans. Geosci. Remote Sensing,vol.26, no. 3,MAY, 1988
[4]Adib Y. Nashashibi ,Fawwaz T. Ulaby, and Panayiotis Frantzis,R. D. De Roo,”Measurement of the Propagation Parameters of Tree Canopies at MMW Frequencies,”IEEE Trans. Geosci. Remote Sensing,vol.40,no. 2,February,2002
[5]K. S. Chen and Chih-Yuan Chu, "Statistical Characterization of Scattering Signals from Vegetation at Frequency Above X-band by Numerical Simulations," JCIEE,vol.10, pp.11-20, 2003 .
[6]Djuric,Dusan,”Weather analysis,”pp70-72 ,1994
[7]John Toftgard and Partcik C.F. Eggers,”Experimental Characterization of the Polarization State Dynamics of Personal Communication Radio Channels,” Prco. IEEE VTC’93, pp65-69
[8]謝光龍, “ Ka波段地面鏈路降雨效應與植被遮蔽效應之研究,” 國立中央大學太空科學研究所碩士論文, 2002
[9]郭志輝,”中華衛星一號Ka波段傳播實驗診斷分析,” 國立中央大學太空科學研究所碩士論文, 2003
[10]陳仁杰,”雨滴粒徑與植被效應對Ka波段電波衰減影響之探討,” 國立中央大學太空科學研究所碩士論文,2005
[11]鞠志遠, “Ka波段台灣地區降雨及地面環境傳播特性研究,” 國立中央大學太空科學研究所博士論文, 2003.指導教授 陳錕山(Kun-Shan Chen) 審核日期 2006-7-22 推文 plurk
funp
live
udn
HD
myshare
netvibes
friend
youpush
delicious
baidu
網路書籤 Google bookmarks
del.icio.us
hemidemi
myshare