數值地形圖圖資數化精度檢核方法之研究

Abstract

資料的品質是決定應用分析成果好壞的重要因素，由於地理資訊系統在各領域的蓬勃發展，使得市面上有更多數值圖資產品如春筍般的出現，並成為開發各空間應用系統的基礎資料。但是各數值產品的生產單位或使用者，可能會因經濟性因素的考量，而無法對數值圖資作較為完整性的檢核。有鑑於此，本研究將以1/25000基本地形圖為對象，設計一套線上檢核程序，來分析目前基本地形圖數值圖資生產過程的精度品質。 經由研究結果顯示，利用較簡單的線性迴歸轉換方式對取樣檢驗區塊作影像校正，即可以獲得的高精度品質的影像成果。藉由此影像成果，可從中獲取取樣圖徵的檢核資料，來和數值圖資針對點、線圖徵的位置精度及屬性分類精度等方面作檢核，同時進行實例計算分析和誤差分佈的圖形表達。期許這些工作將有助於對數值圖資精度的描述，以利於後續數值圖資品質控制及質量分類研究的進行。

The quality of digital data plays an important role on the results of accompanied applications. With the development of GIS, more and more digital products appear on the spatial data market and become the basis of applications. However, a producer or purchaser of these digital products can't perform complete check on these data for economical reasons. This research thus focuses on the design of an on-line checking procedure for 1/25000 digital topographic maps in order to analyze the quality of their production process. Empirical results depict that using the linear regression transformation method in a sample area is the best rectification method for digital image maps. Sample data were extracted from rectified digital image maps to verify positional accuracy and classified attribute accuracy. The decision of errors in the digital maps are discussed by analyzing the uncertainty of samples and the spreading distribution of errors. Procedures developed in this research are expected to be helpful in describing the characteristics of accuracy and to enhance quality control and quality classification of the digital maps in the future.