即時差分系統其定位精度與工作效率已普遍被接受，但應用於林地作業，由於受到觀測衛星數量不足與多路徑效應影響很難達到初始化狀態。本研究利用即時差分設備，測試動態後處理作業模式於林地環境應用的可行性，目的在當即時差分作業無法完成初始化作業時，可立即進行動態後處理差分作業，提高林地測量工作效能。
本研究證實，動態後處理差分測量模式，只要能持續觀測到4顆以上衛星，觀測時間最長10分鐘，平均誤差值可以達到0.407cm以下之精度。葉面積指數愈高，多路徑影響程度越大，定位誤差值相對提高。闊葉林型水平中誤差平均值為0.516m，大於針葉林型0.179m，但相同時間內闊葉林型觀測點位數量大針葉林型，顯示葉部型態對於多路徑影響應具有相關性，而針葉林型樹幹密度大於闊葉林型，影響到觀測衛星數量進而影響測量作業效能。單基站水平中誤差平均值為0.376m，雙基站水平中誤差平均值為0.360m，顯示雙基站作業模式對於提高定位精度並無明顯差異。基線距離方面，中誤差隨著基線距離增長而加大且具有正相關性。

The positioning precision and work efficiency of the real time differential system have generally been accepted, but it should be used in forestland operation; however, due to the lack of the quantity of the observation satellite and multi-path effect, it is difficult to reach ignition condition. The research used the real time differential equipment to examine the feasibility of post process kinematics in a forest environment. The purpose is to take action and deal with post process differential operation and to improve work efficiency in forest measurement when real time differential operation can not accomplish its initialized operation.
This research has proved that, dealing the structure of post process differential measurement, if 4 or more satellites can be continuously been observed for more than 10 minutes, the average error can be reduced to a value under 0.407 cm. The higher the leaf area density exponent, the bigger the multi-path effect, thus the error of positioning rises relatively. Under the horizontal measurement, the broadleaf type forest has a value of average error, 0.516m, which is greater than the coniferous type forest, 0.179m. At the same time, the quantity of the observation position points of the broadleaf type forest is greater than that of coniferous type forest. This shows that the type of leaf has a relative effect on the multi-path more or less. The density of the trunk of the coniferous type forest is bigger than that of broadleaf type forest, therefore, it would influence the quantity of satellite been observed, and again would influence the efficiency of measuring operation. Under horizontal measurement, the average error value of the single based station and double based station are correspondingly 0.376m and 0.360m. This shows that the operation structure of the double based station has no significant effect on improving the accuracy. As for the base line distance, the error would increase when the distance increases. This has shown their positive correlation.

中文摘要…………………………………………………….…….…………..I
英文摘要……………………………………………………………………III
目錄………………………………………………………………………….V
圖目錄…………………………………………..…....………………...........IX
表目錄……………………………………………………………...……... XII
壹、前言……………………………………………..…..…..……..….……..1
貳、前人研究…………………….……………..…………..….……...……..3
一、GPS衛星測量之演進……………………….…….…….…………3
二、GPS之運作架構……………..………….……….….……………..6
（一）太空部分……………………………………………...…….6
（二）地面控制部分………………………………………...…….6
（三）使用者部分…………………………………………………7
三、GPS訊號結構…..………………....……….…….…….…………..8
四、GPS定位方法..……………..……………………….…...………..10
五、決定GPS定位精度之考量………………..……..…..…….…….11
六、影響定位精度之因子…………...……….……….……….…..….12
（一）可掌控因子………………………………………………..12
（二）不可掌控因子……………………………………………..12
七、GPS定位精度等級……………………….……………………….13
八、差分技術………………………………….……….……..….……14
（一）GPS基本理論…………………….………………………14
（二）差分GPS定位原理………………………………………14
（三）後處理差分定位…………………….……….….…..……14
（四）動態後處理差分作業模式…………………….….…..….15
（五）即時動態差分與動態後處理差分……….……..….…….15
（六）廣播DGPS系統設備……………………..….…………..16
（七）DGPS使用者設備………………………………………..18
（八）DGPS運作的四種模式…………………………………..18
（九）DGPS測量型態…………...……………………………...19
九、多路徑效應………………….………...………….....…..….…….20
叁、材料與方法………………………………………..….….…………….24
一、儀器設備………………………………..…….…………………24
二、實驗設計…………………………………………….…………..28
（一）林地環境配置………………………..……………...……28
（二）基準座標取得方式…………………..………….………..28
（三）基線配置方式…………….…………………….…..…….31
（四）單基站與雙基站實驗配置……………………….…..…..31
（五）觀測參數與觀測時間之組合……………….….…...……32
（六）差分解算規則………………………………….…………32
（七）統計軟體………………………………………..….……..33
肆、實驗結果………………………………………………………...……..35
一、差分前與差分後之差異分析.……………………………..……..35
（一）差分前、後之水平中誤差………………….….…...……35
（二）差分前、後之垂直中誤差………………………...……..37
（三）觀測點數量與差分成功率………………….……..….….39
二、定位精度差異與相關性分析………………………….……..…..44
（一）葉面積指數…………………….…………….…..….……44
（二）林型…………………………………………………….…48
（三）基站數量…………………………..………………...……53
（四）基線長度…………………….….………………...………56
伍、結論………………………………………...….……………………….62
陸、參考文獻……………………………………………………………….63
作者簡介…………………………………………………………………….66

曾清涼、儲慶美（1999）GPS 衛星測量原理與應用。國立成功大學衛星資訊研究中心 2: 1-10。

楊名（1997）公分級GPS衛星即時動態定位系統。測量工程39（4）: 1-18。

Abidin, H. (1993) Computational and geometrical aspects of on-the fly ambigulity resolution. Ph.D. dissertation. Dept. of Surveying Engineering Tech. Rep. No. 164. University of New Brunswick. Frederiction. New Brunswick. Canada. 314 pp.

Gili, J. A., J. Corominas, and J. Rius (2000) Using global positioning system techniques in landslide monitoring. Engineering Geology 55: 167–192

Landau, H., U. Vollath, X. Chen, and T. Paper (2002) Virtual reference station systems. Journal of Global Positioning System 1(2): 137-143.

Rizos, C. (2002) Network RTK research and implementation - A geodetic perspective. Journal of Global Positioning System 1(2): 144-150.

Russel, S. S., and J. H. Schaibly (1980) Control segment and user performance. Navigation 1: 74-80.

Seeber, G. (1993) Satellite Geodesy: Foundtions, Method, and Application. Walter de Gruyter& Co. Berlin. Germany.
Shake, C., and J. W. Lavrakas (1994) Inside GPS : The master control station. GPS World. September: 46-54

Sung, H. B., A. H. George, and E. Y. Lawrence (2002) GPS Signal Multipath−A Software Simulator. GPS World. July 2002: 40-49
Trimbe (2001) Trimble Survey Controller Reference Manual Volume 1. January 2001: 116

Washington Department of Natural Resources (2004) GPS GIDEBOOK－ Standards and Guidelines for Land Surveying Using Global Positioning System Methods. 1: 18

林務局（2004）九十三年度施政重點及效益。計畫效益。2005年5月20日，取自：
http://www.forest.gov.tw/web/intro/intro-all.htm

Richard, L., D. Fontana, W. Cheung, P. M. Novak, A. Thomas, and J. Stansell (2001) The Modernized L2 Civil Signal, GPS World.(2001, September) Received January, 4, 2005, from the World Wide Web: http://www.gpsworld.com/gpsworld/article/articleDetail.jsp?id=12195

Trimble Navigation Limited (1997) A New Level of Mapping Accuracy using Everest Multipath Rejection Technology. Received April, 4, 2005, from the World Wide Web:
http://trl.trimble.com/docushare/dsweb/Get/Document-1989/everest.pdf

Trimble Navigation Limited (2004), Why postprocess GPS data? Mapping & GIS White Paper. Received April, 4, 2005, from the World Wide Web:
http://trl.trimble.com/docushare/dsweb/Get/Document-210840/MGIS%20Postprocessing%20White%20Paper_0205_lr.pdf

Tripon Data System (2004) SURVEY PRO for Recon－GPS quick star duide :2. Received April, 10, 2005, from the World Wide Web:
http://trl.trimble.com/docushare/dsweb/Get/Document-173501/TSCe_RangerSurveyProGPSQuickStart.pdf

United State Naval Observatory (2004) BLOCK II satellite information. Received September, 2, 2004, from the World Wide Web: http://tycho.usno.navy.mil/pub/gps/gpsb2.txt