使用航空攝影測量進行地圖更新的首要工作就是求算像片的外方位參數。目前一般航測製圖程序多是以全球定位系統的方式進行地面航測標的控制測量，再將控制點的坐標提供給空三平差程式求算外方位參數。然而這樣的程序對於僅有局部需要更新的都會區航空像片來說，是比較花費時間的。因此本研究試圖利用舊有的數值地形圖和地理資訊系統的資料來解算像片的外方位參數，數值地形圖具有建物屋角點的平面坐標，而地理資訊系統則可提供房屋角點的高程資料。

　　都會區的人工建築物眾多且新舊建物替換的頻率較高，因此地圖更新的需求也相對較高。選取能夠明顯辨識的房屋角點代替航測標，則可以免去外業控制測量的程序，雖然屋角點的坐標精度不如以全球定位系統衛星測量得到的航測標，但大量的人工建物屋角點如同大量的地面控制點，均勻分佈在整張影像上，提供多於航測標數倍的觀測量，不僅可降低航測製圖的成本，也能夠提升成果的可靠度，彌補房屋角點坐標精度的不足。

　　為了測試本研究提出的方法是否能夠有效應用在都會區的局部地圖更新，從整張航空像片上選取了數個子影像，包含了台灣地區都會區常見的建物屋頂種類：平屋頂、山形屋頂和女兒牆屋頂，針對不同的屋頂類型進行實驗與分析。首先對子影像進行包含特徵線萃取、初步篩選的預處理，接著以鬆弛法計算屋角點像片坐標，然後計算像片的外方位參數，最後以此外方位參數計算得到檢核點坐標，和已知的檢核點坐標比較，評估本法的適用性。經實驗證明，利用舊有的數值地形圖和地理資訊系統資料所求算得到像片外方位參數，精度雖然略遜於解析製圖儀的成果，但對於都會區1/1000地形圖局部更新來說，已能滿足精度要求。

　　The very first procedure for map revision is obtaining the exterior orientation. Up to now, for most general photogrammetry, the control surveys are taken by GPS surveying which is however a time-consuming task for local map revision over urban area. In this research, database information, including a digital map and GIS data, is used for exterior orientation.

　　The large-scale maps of built-up area are of special interest if they are to be revised or supplemented with new themes. The existing maps have sufficient and accurate information which could be used to find the orientation of the new images. It would save times using building’s corners instead of the control points. Although the accuracy of the building’s corners could not be as good as those control points, the uniform-located corners would provide a great quantity of observations which could hopefully increase the reliability.

　　To see if the applied method would work efficiently, nine sub-images are abstracted from the original aerial image over urban area, including rectangular buildings with plat roofs, gable roofs and roofs with parapets. After line feature abstracting, relaxation method is used to determine the class of each line features. Space resection is carried out through intersection points from proper line features. The experimental result shows that it is feasible to find exterior orientation by existing digital map and GIS data and would suffice the required accuracy for local revision over 1/1000 map, which is stipulated under 10% of the complement coordinates would be allowed to deviate 20cm exceedingly corresponding to the aero-triangulation points.

王之卓，1984，「攝影測量原理」，武漢測繪科技大學出版社，pp. 14-22

任顯豐，1996，「1/1000航測地形圖精度標之研究」，國立成功大學測量工程研究所碩士論文

吳金昇，1996，「立體影像中矩形特徵物的萃取及對應之研究」，國立成功大學測量工程研究所碩士論文

邱式鴻、王蜀嘉，1996，「Förstner特徵物萃取法精確性的探討」，第十五屆測量學術及應用研討會論文集(下冊)，台北市，pp. 667-676

於宗儔、魯林成，1983，「測量平差基礎」，武漢測繪科技大學出版社，pp. 320-342

胡征懷，1992，「以區塊匹配法自動產生DEM並協助地表變遷偵測」，國立成功大學航空測量研究所碩士論文

徐百輝，1995，「應用Hough轉換於框標及共軛影像量測之研究」，國立成功大學測量工程研究所碩士論文

張智星，2000，「Matlab程式設計與應用」，清蔚科技，新竹

張祖勛、張劍清，1997，「數字攝影測量學」，武漢測繪科技大學出版社，武漢，pp. 213-215

陳世崇，1999，「以屋頂面法線為約制條件協助立體像對中建物邊緣線之篩選」，國立成功大學測量工程研究所碩士論文

傅俊淇，2003，「多重影像中線型特徵物與物空間直線進行匹配之研究」，國立成功大學測量工程研究所碩士論文

楊靈峰，2003，「以現有正射影與DTM資料解算外方位參數」，國立成功大學測量工程研究所碩士論文

廖揚清、何維信、王蜀嘉、曾宏正、趙鍵哲、王成機，1991，「1/1000基本地形圖自動化航測作業暨建檔試辦作業」

Barnard, S.T., Thompson, 1980, “Disparity Analysis of Images”, IEEE Transaction on Pattern Analysis and Machine Intelligence, Vol. PAMI-2, No.4, pp.333-340

Drewniok, C., Rohr, K., 1997, “Exterior Orientation－An Automatic Approach Based on Fitting Analytic Landmark Models”, ISPRS journal of Photogrammetry & Remote Sensing, Vol. 52, pp.132-145

Drewniok, C., Rohr, K., 1996, “Automatic Exterior Orientation of Aerial Images in Urban Environments”, XVIIIth ISPRS Congress, International Archives of Photogrammetry & Remote Sensing, Vol. 31(B3), pp.146-152

Grün, A., Wang, X., 1998, “CC-Modeler: A Topology Generator for 3-D City Models”, ISPRS journal of Photogrammetry & Remote Sensing, Vol. 53, pp.286-295

Höhle, J., 1999, “Automatic Orientation of Aerial Images on Database Information”, European Organization for Experimental Photogrammtric Research, Vol. 36, pp.71-117

Läbe, T., Ellenbeck, K.H., 1996, “3D-Wirefram Models as Ground Control Points for The Automatic Exterior Orientation”, Int. Arch. of Photogramm. & Remote Sensing, Vol. 29(B2), pp.218-223

Morgado, A., Dowman, I., 1997, “A Procedure for Automatic Absolute Orientation Using Aerial Photographs and A Map”, ISPRS journal of Photogrammetry & Remote Sensing, Vol. 52, pp.169-182

Pedersen, B.M., 1996, “Automated Exterior Orientation of Large-Scale Imagery Using Map Data”, Integrating Photogrammetric Techniques with Scene Analysis and Machine Vision III, Vol. 3072 of Proc. SPIE, pp.276-285, Orlando, U.S.A.

Rosenfeld, A., Kak, A.C., 1982, “Digital Picture Processing”, Vol. 2, 2nd ed, Academic Press, Inc., N.Y., U.S.A., pp.152-184

Rosenfeld, A., Hummel, R.A., Zucker, S.W., 1976, “Scene Labeling by Relaxation Operations”, IEEE Transactions on System, Man, and Cybernetics, Vol. SMC-6, No. 6, pp.420-433

Shickler, W., 1994, “Towards Automation in Photogrammetry－An Example: Automatic Exterior Orientation”, Geodetical Info Magazine, Vol. 7, No.4, pp.32-35

Shickler, W., 1992, “Feature Matching for Outer Orientation of Single Images Using 3-D Wirefram Controlpoints”, Int. Arch. of Photogramm. & Remote Sensing, Vol. 29(B3), pp.591-598