地籍圖、都市計畫圖與地形現況圖三圖套疊分析之研究

臺灣地區因時空環境造成地籍圖測繪之坐標系統繁多未能統一，無法與都市計畫圖、地形現況圖等圖資有效套合進行地理資訊系統之加值應用。自TWD97大地基準公布後，因其具高精度、並可配合GPS衛星定位系統作業之特性，大幅提升了測量工作的便利性及地理資料的精度。因此，將各種舊圖資系統整合至該坐標系統，為各地理資料測製機關努力推動之方向。本文討論地籍圖坐標轉換整合標準作業流程：建立TWD97坐標系統控制點與圖根導線網成果後，先以三參數轉換套圖平差求定圖根點圖上坐標，並依據相鄰圖根點於新舊坐標系統中反算邊長分析，劃設地籍圖分區，進行分區六參數轉換，得到界址點轉換後坐標，建立TWD97地籍圖，分析圖資成果與地籍圖、都市計畫圖及地形現況圖三圖套合精度。整體而言，在數值區套合精度較佳，套合誤差在6公分以內之區域約達70%。由於地籍圖的測繪精度最高，於套合誤差較大的區域，在地籍圖正確無誤的前提下，應以其為參考基準，據以修正都市計畫圖及地形現況圖，以使三種圖資能真正達到成果一致。 The coordinate systems of cadastral maps in Taiwan are different. Therefore, cadastral, land-use and topographic maps cannot be overlayed precisely and applied in geographicinformation system. TWD97 coordinate system has the properties of high precision anddirectly connecting to GPS surveying, hence surveying institutions of geographic data makeefforts to generate old maps to this system.In this research, standard procedure of coordinate transformation is discussed. First, thecoordinates of control points in TWD97 are determined. Positions of control points on thecadastral maps are computed by three-parameters-transformation overlay adjustment. Based onthe distance analysis of neighboring control points, transformation zones are determined.Cadastral maps in TWD97 are then generated by six-parameters-transformation. Analysis and overlaying of cadastral maps with land-use and topographic maps are also discussed. Thegeneral results show that the accuracy in digital cadastral map zone is better. About 70percentages of study area, the accuracy of overlaying is less than 6 cetimeters. Considering thesurveying and cartographic accuracy, land-use and topographic maps should be modified basedon the cadastral maps which have been confirmed.

The coordinate systems of cadastral maps in Taiwan are different. Therefore, cadastral,land-use and topographic maps cannot be overlayed precisely and applied in geographicinformation system. TWD97 coordinate system has the properties of high precision anddirectly connecting to GPS surveying, hence surveying institutions of geographic data makeefforts to generate old maps to this system.In this research, standard procedure of coordinate transformation is discussed. First, thecoordinates of control points in TWD97 are determined. Positions of control points on thecadastral maps are computed by three-parameters-transformation overlay adjustment. Based onthe distance analysis of neighboring control points, transformation zones are determined.Cadastral maps in TWD97 are then generated by six-parameters-transformation. Analysis and overlaying of cadastral maps with land-use and topographic maps are also discussed. Thegeneral results show that the accuracy in digital cadastral map zone is better. About 70percentages of study area, the accuracy of overlaying is less than 6 cetimeters. Considering thesurveying and cartographic accuracy, land-use and topographic maps should be modified basedon the cadastral maps which have been confirmed.