Research On The Methods Of Vector Map Data Quality Assessment Based On The Cloud Model

Vector maps have been widely applied in the national economy and the defense construction, and their support to the planning and management in the economic and military activities is increasingly obvious. The quality of vector maps can directly affect the reliability of analyzing results and the application of goal realizing. In order to fully reflect the high tech and high.value of the digital map data and to ensure its vitality, it must adhere to the quality first on the production. In recent years, a number of basic vector map databases on different scales have been completed using the traditional production methods and quality evaluation methods. These old methods are difficult to acquire accurate and objective data quality assessment, which directly affect the production of high quality vector map. There is an urgent need for systematic and comprehensive theory of comprehensive assessment of vector map data and technology research, in order to provide good potential, highly accurate, reliable, complete digital map products for national economic construction and social development. Based on the analysis of the characteristics and influencing factors of vector map data quality, this paper focuses on the vector map data quality assessment methods and techniques. The main work and innovations are as follows:1. Analyze the status and development trend of geospatial data quality, according to the quality of the basic elements of international geographic information standards and national standards for digital map products. The quality elements for vector map data are presented based on the content of the quality testing, which is the basis for quality assessment;2. The cloud theory is applied in the field of vector map data quality assessment. The feasibility of using cloud model to evaluate the quality of vector map data is analyzed in depth. The cloud model can combine the randomness and fuzziness with expected value, entropy and hyper entropy and it can get the assessment value according to one conception via a specific algorithm. Experiments show that this quality assessment method is more objective and accurate than the previous evaluation, and its evaluation results can be showed intuitively and delicately;3. Automatic quality assessment for vector map data has been achieved. The "vector map data quality assessment subsystem" platform is built based on the mapcheck software exploited by the Xi'an Institute of Surveying and Mapping.