Quality Analysis On Crowd Sourcing Geographic Data With OSM Road Network Data

In the Internet era,users have changed from the single role of information receiver to the dual identity of information user and provider.This information mode of user co-creation and sharing is called information multi-source,which greatly enriches the network data.Information multi-source is applied to the collection and acquisition of geographic information data,that is,multi-source geographic information.Because of its large amount of data,rich content,strong current situation and many other characteristics,as well as the convenience and connectivity of the network,crowdsourced geographic information is widely used in scientific research and business applications.The OpenStreetMap(OSM)project is one of the representative projects.Compared with the high labor cost of traditional surveying and mapping data,OSM has attracted great attention because of its free and open source characteristics.However,since the data of OSM is mainly provided by non-professional surveying and mapping personnel,the quality of OSM data as a supplementary data source of traditional surveying and mapping data is questioned.Therefore,the quality of spatial data needs to be evaluated before use.The research on the accuracy,integrity and reliability of attribute text data and geospatial data of spontaneous geographic information data(OSM)is conducive to providing quantitative basis and data reference for the subsequent application based on OSM,so as to promote the rational use of OSM in domestic medical rescue,road navigation,and path analysis.In domestic and abroad,the evaluation researchers of the multi-source geographic data mostly use a single evaluation index for analysis,lack of integrated comprehensive evaluation mode,so the evaluation results of the data are one-sided,lack of comprehensiveness.This paper selects the OSM road network data in Qingdao as the research data source,and takes the MapWorld road network data in this area as the reference data to evaluate the quality and availability of the OSM road network data.Based on the evaluation and analysis of each single level index of road network data,this paper combines GIS spatial analysis and fuzzy mathematics,and establishes the evaluation index system and fuzzy comprehensive evaluation method of OSM data by using FAHP and the entropy weight method.Firstly,the quality evaluation system of road network data is established,the evaluation objectives and factors are established,and the evaluation grade is divided;secondly,the quality of the underlying data indexes of OSM road network data is analyzed from the four aspects of integrity,attribute precision,geometric precision and topological accuracy;thirdly,the subjective weight is determined by the fuzzy matrix,the original data matrix of entropy weight method is established,and the objective weight is calculated Value;then use the optimized combination weight method to carry on the weight combination,finally take this as the basis to carry on the quality comprehensive evaluation.The results show that the evaluation indexes and methods established in this paper are feasible and practical.the topology accuracy is high in general,and the collection process is relatively standardized.Through the analysis of this method,it is concluded that the national and provincial roads and other roads in the OSM road network data of Qingdao municipal area are of medium grade,the county and township roads are of general grade,while the pedestrian roads benefit from their rich geometric integrity and the evaluation grade is excellent.As the evaluation results of attribute integrity and attribute accuracy are low as a whole,we should further guide and standardize the integrity and accuracy of volunteers when uploading attribute data,so as to improve the availability of low-level road data.In addition,although the overall trend and orientation of the OSM road network data are consistent with the reference data,there is a certain degree of deviation in the location accuracy of some sections,resulting in the low statistical value of the final location accuracy.The geometric data can be corrected from the overall location correction direction to improve the accuracy level.The accuracy of high-level roads such as national and provincial roads is higher than that of low-level roads such as pedestrian roads in attribute accuracy,spatial accuracy and topological accuracy,while the richness of pedestrian roads and other roads compared with traditional mapping data,so the OSM road network data can be used as a supplementary data source of traditional mapping data.