Research On Geographic Information Retrieval Method For GML Data

With the implementation of GML international standard(ISO 19136-2007)and GML China National Standard(GB/T 23708-2009),the rise of volunteered geographic information(VGI)system and the increasing popularity of web feature service(WFS),GML data springs up with its rich semantic expression,powerful data model and open data structure,and forms a unique geographical information resources on the Internet.The development of geographic information retrieval method of GML data can improve the retrieval ability of current Internet electronic map and enrich its content of data.However,the traditional XML and geographic information retrieval in GML data are facing some problems,such as the mismathing of retrieval model,the leaning in retrieval schema and the inaccuracy of retrieval results.Given this,this paper summarizes the retrieval schema of GML data and proposes a geographic information retrieval model(GML_GIR)based on GML features by the studing and anlaysing of GML data model,features and application scenarios,enrichs the geographic information retrieval form,explores the geographic information retrieval of semi-structured data represented by GML.In this paper,the main research contents and results are as follows:(1)Geographic information retrieval schema of GML is studied based on analysing GML data mode,feature and its application scenarios.GML data retrieval schema is represented formally in atrribute feature,spatial relation feature and structure feature.This retrieval schema puts attribute feature,spatial relation feature and structure feature of GML data as the retrieval feature,builds a foundation of the studing of retrieval mode and method.(2)Studyies the retrieval model of GML data on the base of retrieval schema of GML data.This paper proposes a Geographic Information Retrieval Model for GML(GML_GIR)on the base of the existing results of geographic information retrieval model,designs a similarity calculation method in atrributes,spatial relation and structure for sorting of retrieval results.(3)This paper constructs a geographic information retrieval framework of GML by using GML_GIR and the open source retrieval engine of full text Lucene.Contructs the index of attributs text atrributes numerical value,spatial relation and structure information by using Lucene and its spatial component Lucene Spatial.Impoves the similarity score module of Lucene by using the GML_GIR similarity calculation method.The effectiveness of GML geographic information retrieval method is verified by experiments.The results show that,this retrieval method realizes the retrieval way based on GML data characteristics and statisfy the efficiency and accuracy requirements of the retrieval.