近年我國最重要的國家級測量工作，為以4年時間建置完成台灣本島一等水準網，藉由整合水準、重力、以及GPS觀測量，建立一個高精度之國家高程系統－2001年台灣高程基準（Taiwan Vertical Datum 2001，TWVD2001）。目前已完成TWVD2001一等一級水準網測量，共計有1010個一等一級水準點，分布在約2200公里之水準線上。本研究之目的在於使用理論上較完備之大地位數（geopotential number）平差模式，整合處理一等一級水準測量和重力測量觀測資料，以檢驗傳統以正高改正(orthometric correction)方式所得之水準網平差成果。以大地位數為基礎之水準網資料分析，除了可以得到水準點之正高(orthometric height)，亦能同時獲得正常高(normal height)及力高(dynamic height)之資訊，可作為定義台灣高精度高程系統之重要參考依據。
　　本研究顯示，傳統平差方法與大地位數平差模式可得到幾乎相同之一等一級水準點正高值，成果較差之平均值為-0.01mm，標準偏差僅為 mm。比較由大地位數所得之一等一級水準點正高（參考於大地水準面，無法嚴密計算得到）與正常高（參考於似大地水準面，可嚴密求得）值，在水準原點處（基隆）之差異量僅為-0.06mm，在高程100公尺以下的平地區域內之差異量為-6.78~5.96mm，顯示這兩種高程在平地處非常接近，均可滿足國家建設之需求。且隨著高程之增加，兩種高程之差異亦增大，在中橫山區最高水準點處之差異量已達到226.66mm，但是在花東縱谷與東南部一帶隨著高程之增加，兩種高程之差異卻往負的方向增大，在花東縱谷最高水準點處之差異量達-38.80mm。

　　Recently the important national surveying work of our country is to establishing a high precision national vertical datum system (Taiwan Vertical Datum 2001, TWVD2001) by using integrated leveling、gravity and GPS observations. It is for constituting the first-order leveling network of Taiwan by four years. Now the surveying work of first-order leveling network which including 1010 first-order benchmarks and being distributed the leveling-line around 2000km. has been completed. The purpose of this research is to utilizing the comparative perfect theory of the geopotential number adjustment model integrating observations of the first-order leveling surveying and gravity surveying in order to check the adjusted results of leveling network which have been acquired by traditional orthometric correct method. The analysis of leveling network data in the geopotential number-based can attain the orthometric height of the benchmark; moreover the information of normal height and dynamic height can be the important reference basis of providing to define the Taiwan high precision vertical datum system.

　　This study shows that the traditional adjustment method and the geopotential number adjustment model almost attain the same orthometric value result of the first-order benchmarks. The average value of the results’ comparison value is –0.01mm, and standard deviation is . Comparing the orthometric height value of the first-order benchmarks which refers to geoid are not being calculated strictly and the normal height value which refers to quasi-geoid are being calculated strictly shows the difference of only –0.06mm on the origin benchmark(Keelung) and the difference of –6.78 ~ 5.96mm in lowing 100m height’ plains. These mean the two heights meet very close in the plains and therefore reach the national building demand. Two heights’ difference is following the height raising and reaching 226.66mm on the highest benchmark of the center cross mountain area. But following the height raising in the Hual-Tung valley and southeast areas, two heights’ difference is increasing contrarily and reaching –38.80mm on the highest benchmark of the Hual-Tung valley area.

尹鐘奇，實用大地測量學。國彰出版社，台中，1976。

內政部，一等水準測量作業規範。台北，2001。

孔祥元、郭際明、劉宗泉，大地測量學基礎。武漢大學出版社，南京，2001。

胡明城、魯福，現代大地測量學上冊。測繪出版社，北京，1993。

胡明城、魯福，現代大地測量學下冊。測繪出版社，北京，1994。

高書屏、許榮欣、甯方璽、孫福生，台灣一等水準網精度研析。第十五屆測量學術及應用研討會，國立政治大學，台北，575-584頁，1996。

許榮欣、高書屏，台灣地區一等水準網測量殘留之系統誤差之研究。行政院國家科學委員專題研究計畫成果報告，台北，1996。

郭俊義，物理大地測量學基礎。測繪出版社，北京，1994。

陳俊廷，聯合水準、重力、GPS觀測資料之台灣高程系統精度預估。國立成功大學測量工程研究所碩士論文，台南，1997。

國立成功大學，一等一級水準網測量督導查核工作總報告書。台南，2001。

國立交通大學，一等一級水準點上實施重力測量工作報告書。新竹，2001。

張嘉強，精密水準測量中重力與大氣折射之系統誤差研究。國立成功大學測量工程研究所碩士論文，台南，1987。

黃金維，衛星及重力法台灣高程系統。第十五屆測量學術及應用研討會，國立政治大學，台北，495-501頁，1996。

黃金維、蔡進雄，衛星及重力法台灣高程系統。第十六屆測量學術及應用研討會，中正理工學院，桃園，39-47頁，1997。

管澤霖、寧津生，地球重力場在工程測量中的應用。測繪出版社，北京，1990。

劉啟清，精密水準測量之系統誤差。第五屆測量學術及應用研討會論文集，F1-F25頁，1986。

劉啟清，台灣地區驗潮站長期監測資料之計算及高程基準網之建立工作。中央研究院地球科學研究所專題研究計畫成果報告，中央研究院地球科學研究所，台北，1998。

劉啟清，台灣地區驗潮站及高程基準網之監測及計算工作。中央研究院地球科學研究所專題研究計畫成果報告，中央研究院地球科學研究所，台北，2000。

劉凡正、劉文俊、張瑞剛、管麗琴、戴益寶、蔡文富，基隆平均海水面及水準零點再確定之研究。第十六屆測量學術及應用研討會，中正理工學院，桃園，291-304頁，1997。

聯勤測量署，大地測量手冊。1978。

Ahmad, Z., Kearsley, A.H.W., and Harvey, B.R., Optimizing GPS, geoid and tide gauge heights in vertical control networks, In Contributions to Geoid and GPS Height (ed. Kearsley, A.H.W.), UNISURV S-43, School of Surveying UNSW, Australia, pp. 127-209, 1993.

Bomford, G., Geodesy, 4th Ed., Oxford University Press, New York, 1980.

Caspary, W.F., Concept of network and Deformation Analysis, Mon. 11, School of Surveying, University of New South Wales, Kensington, Australia, 1987.

Fury, R. J., Leveled height differences from published NAVD88 orthometric height, Surveying and Land Information Systems, Vol. 56, No. 2, pp. 89-102, 1996.

Heiskanen, W.A., and H. Moritz, Physical geodesy, W. H. Freeman and Co., San Francisco and London, 1967.

Hsu, R., Convergence of the variance of unit weight in a levelling network adjustment, Survey Review, 33, 260, pp. 404-410, 1996.

Hwang, C., Analysis of some systematic errors affecting altimeter derived sea surface gradient with application to geoid determination over Taiwan, Journal of Geodesy, Vol. 71, pp. 113-130, 1997.

Hwang, C., Height system of Taiwan from satellite and terrestrial data, Journal of Geodesy, Vol. 123, No. 4, pp. 162-180, 1997.

Jackson, D.D., W.B. Lee, C.C. Liu, Height Dependent Errors in Southern California Levelling, Earthquake Prediction: An International Review, AGU, pp. 457-492, 1981.

Jekeli, C., Height, the Geopotential, and Vertical Datums, Geodetic Science and Surveying, Department of Civil and Environmental Engineer- ing and Geodetic Science, The Ohio State University, Columbus, OH, Report No. 459, 2000.

Liu, C.C., Tectonic Interpretation of Levelling Data in Southern California, UCLA Ph.D., Thesis, 1985.

Rizos, C., The Role of the Gravity Field in Sea Surface Topograthy Studies, UNISSURV S-17, School of Surveying UNSW, Australia, 1980.

Rapp, R.H. and Balasubramania, N., A Conceptual Formulation of a World Height System, Report No. 421, Department of Geodetic Science and Surveying, The Ohio State University, 1992.

Seeber, G., Satellite Geodesy：Foundations, Methods, and Applications, Walter de Gruyter, Berlin, 1993.

Torge, W., Geodesy, 2nd Ed., Walter de Gruyter, New York, 1991.

Vanicek, P. and E.J. Krakiwsky, Geodesy： the concepts, North-Holland Press, Amsterdam, 1986.

Vanicek, P., Vertical datum and NAVD88, Surveying and Land Information System, Vol. 51, No. 2, pp. 83-86, 1991.

Zilkoski, D.B., Richards, J.H., and Young, G.H., Results from the general adjustment of the north American vertical datum of 1988, Survey- ing and Land Information System., Vol. 52, No. 3, pp. 133-149, 1992.