| Spatial data is the foundation of the generation and application of geographic information data.With the continuous expansion of the application range and the continuous deepening of the application level of the geographic information data,the high quality of global geographic information application is put forward the urgent request by users.But now,the manufacture and production of the geographic information data in overseas areas could only rely on the public information collected from the Internet,which existed many problems such as difficulty in collection,mess and complication of the collected information,poor current situation and exist many inconsistencies,which have seriously affected the quality and efficiency of data production.However,volunteered geographic information is the emerging geographic information data in recent years,with the characteristics of high coverage,high potential,easy to access,etc.In this paper,VGI road data is used to study the quality evaluation of VGI data,the fusion processing of geometrics data,the fusion processing of attributes and so on,in order to provide brand new data for the production and updating of the global geographic information data,scientific quality evaluation and fusion processing methods for the data derived from the network,theories and technical supports for the improvement of geographic information processing efficiency,as well as data production efficiency and quality.The main work accomplished and the results achieved in this paper are as follows:1.The urgent request to global geographic information data for users is analyzed,and the research situation at home and abroad about the quality evaluation method of the VGI data,the fusion of the multi-source spatial vector data,etc.are summarized by surrounding the key technologies involved in the quality analysis and fusion processing to the VGI data.The shortages existed in current research are summed up,then,the main research content is proposed in this paper.2.Through the brief introduction about the background of the generation of the VGI data,and the comparison among related concepts,the classification and characteristics on VGI data are summarized,and the questions about the uncertainty of data quality,the complication of geometric data detail,the inconsistency of attributes information,etc.faced during the application of data production and updating of VGI data are analyzed emphatically.Based on the detailed discussion on the causes of the formation of the mentioned questions and responsive measures can be taken,the technology framework and processing workflow on the quality analysis and fusion treatment of VGI data are put forward in this paper.3.On the basis of the summary about the factors those influencing VGI data quality and the goals of data application,the evaluation factors of VGI data quality and the evaluation methods upon vector reference data are raised in this paper,aiming to elaborate the completeness of data,the connotation and measurement of geometric position accuracy.In addition,these methods have been verified.On account of the situation of no reference data,a quality evaluation method based on data credibility is proposed,using volunteers' reputation and the trend of data changes to reflect the quality status of VGI data.A way of modifying the geometric accuracy of VGI data by using high-revolution remote sensing image is proposed to solve the problem of insufficient accuracy of some areas.4.Aiming at much of the existing microscopic road structure in VGI,a recognition algorithm of road microstructure based on support vector machine is raised,which uses the idea of road segment classification to identify and simplify the overpass and complex road intersections in VGI data.To improve the fusion processing efficiency of road network,an algorithm of road network selection based on weighted webpage sorting is proposed by using the principle of webpage sorting to calculate the importance of road in road network,which is the basis of proceeding road selection.Directing at the characteristics of VGI road in rich details,scale-free property,etc.a VGI road network matching algorithm based on dual graph is proposed,which utilizes the feature of invariability of the road connection relation before and after the scale change to match road network.5.From the aspects of the classification and attribute segment of the elements,this paper analyzes the difference between the VGI attribute data and the reference data,and states a mapping transformation method between VGI attribute data and the classification and attribute segment in reference,also sets forth the concrete mapping transformation types and points for attention in transformation.So as to facilitate the storage,editing and maintenance of transformation rules,a mapping transformation method based on production rules is proposed by using XML language to express the transformation rules,and the response elements transformation templates are built according to the difference of transformation elements in transformation rules,also the mapping transformation workflow based on rule template is designed in this paper.6.By mean of the design and implement of VGI data quality analysis and fusion processing system,the experiments about quality evaluation,microstructure identification,road network election,road network matching,attribute data transformation,etc.are taken to verify the related processing technologies mentioned in this paper. |
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