Research On Technology Of Consistency Processing For Multi-sources Spatial Vector Data

With the rapid development of acquisition and processing technology for spatial data, the types of spatial data are increasing. Because acquisition channels and acquisition time are different, and these spatial data are produced by different sectors or countries, therefore, mathematics basic, spatial datum, scales, currency, encods and formats are inconsistent and uncoordinated. To improve the quality and the existing potential of spatial data, we must solve the inconsistency of multi-sources spatial data in the above-mentioned aspects. The paper analyzes technology of consistency processing for multi-sources spatial data deeply. Based on the existing multi-sources and multi-scales spatial data, it researches on inconsistencies of geometric position, attribute features and spatial relationships for multi-sources spatial data, and achieves the organic unity of the multi-sources spatial data in the location, attributes and relationships, and improves the quality of spatial data. The main contents of this article are as follows:(1) The basic problems of consistency processing for multi-sources spatial data. The paper analyzes multi-sources spatial data, and summarizes reasons of the inconsistency for the multi-source spatial data are as follows:the various factors of the coordinate system, map projection, data model, data applications, spatial data production and regeneration patterns and spatial data errors etc. The paper also analyzes aspects of the inconsistent performance for multi-sources spatial data respectively, such as geometrical position, spatial relationships, properties and temporal features. Finally, multi-sources spatial data consistency process is brought forward.(2) The consistency processing of geometric position for multi-sources spatial data. The paper generalizes the basic theory and methods of the coordinate system conversion map projection conversion and geometric correction. Based on the above theory and method, it puts forward the consistency processing of geometric position for the image and vector data. For the road features in the spatial data, the paper uses the Otsu algorithm for image segmentation on the image of the road, and matches road intersections in the image with priori knowledges of vector, then two sets of road intersections are as control points. Finally, we constructs Delauny triangle to realize the consistency processing of geometric position for the image and vector data.(3) The consistency processing of attribute characters for multi-sources spatial data. The paper analyzes and summarizes the inconsistencies of attribute characters,which are generated by the different classification and grading standards, the different description in details of attribute characters for multi-sources spatial data. For different semantic standards, the paper brings forward the method to transform attribute characters based an external control file; for the same semantic standards, it puts forward the method to merge attribute characters based on same entity matching.(4) The consistency processing of elements relationship for multi-sources spatial data.In the application process spatial data are from different sources, which may lead to the contradictions the elements relationship. For the relationship between roads and residentials, it describes the approach to solve the relationship between these elements.In addition, the consistency processing of geometric position will lead to changes for elements relationship of the vector data, results in inconsistent of elements relationship. Classification and description of elements relationship are brought forward, the paper proposes the method to judge the consistency of spatial data based on the matrix difference of elements relationship, and handles the consistency of elements relationship under the guidance of processing rules.(5) The above research results for multi-source spatial data are utilized In many GIS data production softwares and systems. The paper verifies the correctness of processing techniques and methods in the consistency, part of the technology has been applied to actual production...