| Summary: | 碩士 === 逢甲大學 === 土木工程學系 === 105 === The digital map is one of necessities that people cannot live without in modern society. Regularly maintaining the quality of digital maps is an important task for works of map digitalization. In the last decades, both governmental digital maps in Taiwan, “Transportation Road Network Digital Atlas” and “Taiwan e-Map”, had been digitalized and issued independently by the Ministry of Transportation and Communications and the Ministry of the Interior, respectively. Despite both maps were usually digitalized by different companies, they adopted the aerial images from Aerial Survey Office of Forestry Bureau, Council of Agriculture, Executive Yuan, as the source image for digitalization. Based on this fact, this study first proposed and developed an algorithm of examining data completeness for digital maps, which compares the differences of geometric data between two above-mentioned governmental maps and distinguish the omission and commission of road segments. Then, we designed a statistical experiment where the results of difference analysis between two maps are used to process four statistical tests. The test result shows that the omission rate and the commission rate calculated by the difference analysis of two governmental maps can be considered as the estimated value of actual data completeness.
In other words, when examining the data completeness of both digital maps, the examiner can use the algorithm proposed by this study to carry out the difference analysis, and then visually matches those road segments with source aerial images to see if the differences are correct. This result can be considered as the quantified estimates of actual data completeness. In this way, the time and costs of manual work can be largely decreased and the credibility of examination result can thus be increased. If those road segments in two maps are corrected accordingly, the benefit of the information fusion will be received. The result of this study can also provide a difference analysis for different versions of a governmental digital map in different times of digitalization, which can better make sure the data completeness and correctness of digital maps.
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