- 學位論文
向量圖資之幾何套疊分析
Integration of vector maps based on multiple geometric features
摘要
地圖是記錄與表達地理資訊的最佳利器，考量資料保存之便利性以及圖資幾何特性，又以向量數值地圖最為普遍，並可利用坐標轉換，使兩種以上的圖資在同一基準下以進行套疊整合分析。坐標轉換包含選用轉換模式與觀測量來建立觀測方程式，並求解轉換參數，最後再進行品質評估。傳統坐標轉換以控制點為觀測量，並設置檢核點為評估轉換成果之標準，故控制點與檢核點的分佈和數量將影響解算成果以及品質評估之客觀性。本研究在坐標轉換的過程中，加入線特徵的方向向量以及投影點做為觀測量，藉以改善單一點觀測量在數量以及分佈上的限制，並提升圖資套疊之整體精度。此外，利用投影增加檢核點來評估絕對位置的精度，並同時以線特徵的相對形狀指標來評估轉換成果，使評估過程更為客觀。透過數值實驗成果顯示，混合觀測量能考量圖資的絕對位置與相對形狀之品質，並改善控制資訊分佈不均，使轉換成果更合理，而多特徵的評估方式也可得知位置與形狀的幾何品質以及合理性，為向量圖資的套疊過程提供較全面的考量。
並列摘要
Map is one of the most intuitive tools in recording and representing the geographic information. Under the consideration of preserving cartographic data in a compact and efficient manner, digital maps composed of vectors are mostly used. Also, users can apply coordinate transformation to analyze data with different datum definitions. A complete coordinate transformation analysis includes model choosing, observation using, parameter estimation, and quality assessment. Typically, control points are used as observables to solve transformation parameters, while check points are used for a quality assessment. As a consequence, poor distribution or an insufficient number of control/check points might lead to a biased transformation solution. In this study, linear features and projective invariant points were both used as observables in a coordinate transformation analysis between multiple vector maps. The goal was to provide a better geometric constraint for the transformation. Furthermore, two numerical indices, namely the absolute consistency and relative similarity, were used for evaluating the quality of a transformation solution. Based on the case studies using both simulated and real datasets, it has been proven that the proposed approach is capable of fully making use the geometric connotation inherent in a vector map and providing a comprehensive quality evaluation on the obtained transformation. Consequently, a more reliable and robust integration analysis for digital vector maps can be achieved when the proposed approach is implemented.