Research On Data Conversion,matching And Quality Assessment Between Volunteered Geographic Informatiom And Professional Data

With the development of Web2.0 technology,sensor technology,as well as the global information technology and digital high-speed,the platform based on users to create geographic data gradually rises,Various of geographic data are collected and shared by the public to some public service platforms,e.g OpenStreetMap(usually referred to as OSM),Wikimapia,Flickr.These geographic data is called Volunteered Geographic Information,which allows the public to participate in the data sharing platform.VIG has a great difference with GIS professional mapping data in the data collection and updating methods.Global volunteers can upload and update geographic data timely without mastering the complex GIS professional skills,therefore the data has advantages on fast update,strong potential and free access etc.But VGI volunteers do not have GIS professional skills,resulting in VGI data has many shortcomings,for instance it doesn't meet the standard specifications,data topology loss.And in recent years China's information technology develops rapidly,we have a great demand for geospatial data,besides we continue to increase the requirements on the current situation of the data requirements.Considering the advantages of VGI data,it is of great significance to analyze the advantages and disadvantages of VGI,avoiding weaknesses,and processing VGI data into standardized geographic information.It is of great significance to the development of geo-spatial information industry in China.In order to study whether VGI can be used rationally,this article uses the more successful case OpenStreetMap platform as a case.Firstly,the data organization form of OSM is studied,analyzing the structure of data.The relationship between mapping and transformation between OSM and professional surveying and mapping data is given.Secondly,we study the matching method between OSM network and professional network,so as to improve the position accuracy of OSM road network.Finally,the data quality of OSM network is evaluated from the aspects of data integrity and location accuracy.The main work of the paper is reflected in the following aspects:1)Establishing the mapping relationship between OSM data and professional mapping data.In order to realize the comparison between OSM and GIS professional survey data,the organization of OSM road network is analyzed firstly.According to the format of GIS professional surveying and mapping data,and the classification of the OSM Tag is made with reference to national standard(GBT 13923-2006 basic geographic information element classification and code)OSM data mapping for the professional mapping data belongs to the topic category,get OSM data and professional mapping data of residents and their facilities,water system,traffic factor,pipeline,geomorphology,vegetation and soil and other six large features layer mapping results.2)A method of matching and transforming multi-scale road network based on grid is proposed.Compared with GIS professional network data,there is a large position deviation,non-systematic deformation and other issues in OSM road network.In order to improve the accuracy of OSM road network location and solve non-system deformation and other issues.Based on the analysis of the characteristics of OSM road network,this paper establishes the multi-scale structure of road network,which makes the expression of complex road network spatial features have rich hierarchical characteristics.In this paper,the multi-scale road network matching transformation method based on grid is proposed,and the experiment is carried out with the actual road network data.Experiments show that this method has higher matching precision and stronger adaptability to complex OSM road matching.3)Data Quality Evaluation Method of OSM Road Network.Based on ISO Geographic Information Data Quality International Standard 19113 which gives a description method of three quantitative quality elements,such as data length integrity,road name attribute integrity and road location accuracy.The reference chooses the four cities,large and medium-sized cities at home and abroad as the experimental areas,and compares to professional surveying mapping data and map of Baidu from the length and road name attribute integrity,road positioning accuracy.Though the experimental verification,compared with the professional surveying mapping data road network,OSM positioning accuracy is higher,length and road name attribute integrity is low in Ganzhou experimental area;compared with Baidu map road network,OSM road network data integrity and current situation have no great difference in the domestic two cities,yet it has obvious advantages in foreign countries.If making further processing on the OSM road network data,it can be used as a professional road network data,and improve its application value.