Methods of Crowd Sourcing Geographic Data Processing and Analysis

Objective Crowd sourcing geographic data(CSGD)is a new kind of open geospatial data collected andprovided to citizens or organizations by non-professional volunteers.Its acquisition differs from con-ventional methods of surveying and mapping.It has the characteristics of being up-to-date,informa-tive,low cost,and large size.Unique issues of such data are its heterogeneous data quality,redun-dancy and incompleteness,uneven data coverage,absence of data standards,privacy and safety,etc.It can be employed in a wide range of application fields including emergency cartography,early warn-ing,map and database updating,crime analysis,and epidemiologic studies.Thus,it is important tosystematically investigate the key aspects regarding its processing and analysis.The paper reviews theprogress and challenges of CSGD processing and analysis.Firstly,the paper summarizes the conceptand characteristics of CSGD.Secondly,the paper introduces the acquisition methods and potential da-ta sources of CSGD.Thirdly,the paper discusses some key methods and techniques on the processingand analysis of CSGD,which includes data quality metrics,information extraction and updating,spa-tial data analysis and mining.Specifically,the paper suggests that firstly data evaluation is a criticalprerequisite for CSGD research and application,secondly information extraction and updating via CS-GD can complement the conventional methods of geographic database updating,and finally spatial dataanalysis and mining on CSGD can provide valuable information and knowledge for potential applica-tions using methods like network topological analysis,spatial statistical analysis,and spatial datamining.Lastly,the paper draws some conclusions on the state-of-the-art of CSGD processing and a-nalysis and points out the future research directions.