Loss Map Data Quality Control Theory And Practice

The precision analysis and quality control of spatial data is one of the main contents of the research on geographic information science. The vector map data is an important presentation of spatial data, its quality influences directly the analysis of all the applied system based on the map data, the correctness and the reliability of the decision and the success of the system. Therefore how to perform the map data quality control becomes a very important problem in the digital information engineering of military surveying and mapping. Based on the analyses of the map data quality standards, data model characteristics, feature coding, various specifications and rules, the paper researches and discusses thoroughly the technology and method for vector map data quality check, evaluation and control both in theory and in practice. The main contents are as the following:(1) Analyzing various operation specifications and standards for the digital information engineering of military surveying and mapping; and proposing the evaluation model for vector map data quality based on the quantification of the specifications and standards.(2) Researching the position error of the scanning digital objective and checking the distribution fitting of the attributes, measurement index and distribution regularity of the errors based on the description of the causes and meanings of the map data error; and putting forward several methods for the adjustment of the map data.(3) Resolving the symbolization check and presentation of the map attribute data based on the visual variants and visualization technology; automatically checking the range of the value of the attributes and logic consistency and integrity based on the attribute template technology. The users can evaluate, improve and optimize the precision of the attributes according to the checking results and print the map of the checking results as well as the resulting map consistent with the specification requirements.(4) Designing a convenient and practical visulization method for checking topologic relation and geographic name; modifying and reorganizing topologically the wrongly topologic information.(5) Designing the method combining automatic seaming with interactive seaming to remove the seaming error between the map sheets; providing many editing tools for all the errors having been found.(6) Designing and realizing the prototype-MapCheck software by combing with the need for the digital information engineering of military surveying and mapping to establish series-scale map database; describing in detail the structure, function and the realization method of MapCheck.