| dc.description.abstract | Geographic information plays an important part in people’s life. Especially with the development of computer science and Internet. GIS also went into a new era, from paper works to digital formats. The digital geographic data files can be spread and shared fast and widely via Internet. However, establishing new geographic data is expensive, thus the data users are not always the data establisher. In the hight speed developing GI society, many private sectors have participated in geographic data production, and also many datasets are from unclear sources with unclear quality information. In addition, errors can be generated during the transform and transfer processes. Therefor proper geographic data quality control and management is in urgent demand. GML is an XML-formed document for geographic information. It is a young but fast developing geographic data format, with its natural advantages, it is now being considered as standard geographic data format world wide. This project is concerned with the data quality control for GML files. Data validation is one kind of data quality measurement method in the data quality control process. The thesis aims to build up a validation framework for GML files based on the Norwegian standard. In the report the geographic data modeling is first described, including the Norwegian road network production specification, simple feature specification, and the related GML knowledge. The data quality issues are introduced after the modeling, the data quality issues are elaborated from two levels: general inconsistency level and specific ISO data quality element level. Following is the introductions, discussions and comparisons to the existing relevant geographic data quality tools. And at the ene the final GML validation framework is determined. | en_US |
