Research On Key Technology Of Spatial Information Service Chaining

Along with the continuous expansion of spatial information applicationrequirements, the problems of heterogeneous distributing, complex handling and,intensive computing of vast amounts spatial data have become to important factors onrestricting application of spatial information widely sharing. The proposed web serviceand its development have set new direction and trend for the internet ApplicationService Systen of different levels and departments. Web service offers a newintegration idea for spatial information sharing and serving, that is spatial informationweb service. The spatial information web service effectively solves the problems ofspatial information sharing and interoperating on the distributed and heterogeneousenvironment, it is the main research direction and way to realize distritited spatialinformation sharing and serving widly. The constantly enrich spatial informationservices on the internet or within the organizations, makes how to dynamicallycomposite the existing spatial information web services to form a new value addedservice to be currently an improtmant spatial information application construct model.Therefore, the technic of spatial information service chain has become a new researchfocus in the field of geographic information science. Focusing on the shortcomings ofcurrent spatial information chain study, this paper has lucubrated on the spatialinformation service technology system, spatial information service managementmechanism, spatial information service chain business process modeling anddescribing, spatial information service chain validating and implementing ect. Specificcontents are as follows:(1) Base on studying the theory of spatial information service chain concept,model, constructing methods, and correlative supporting technology, spatialinformation service chain technology system is proposed.(2) Taking the application requirement of regional spatial information sharing andserving as the background, the spatial information service classification system face onregional user application requirement is advanced, base on analyzing the spatialinformation service classification method of OGC,ISO and other scholars.(3) Base on analyzing the problems of the existing spatial information registrycenter, the spatial information service management mechanism system is put forword,which gathers spatial information service searching, describing, classificating,organizating, and storaging, releasing and finding to be one. And has built the servicedatabase management center of regional spatial information application field to registerand manage the spatial information service. The service database management centernot only stores the basic information of service, also stores the quality attributes ofservice and service relationships, to provice users with the service finding way of query classification query, keyword query, cnstraints query, associated query andcomprenhensive query(4) After comparing the existing service chain process modeling and processdescription method, service chain process modeling method is proposed based onactivity network diagram, and has provided a visual platform for users to model theservice chain process and to describe the node attributes using natural language.(5) Parsing the requirement model, basing on XML specification,taking webservice Business Process Execution Language(WS-BPEL)as the foundation,trough thenecessary changes,additions and simplify, the Spatial information Service ChainDescription Language SSCDL is advanced for the characteristics of spatial informationservice chain dynamic changing.SSCDL structural describes the requirement mode ofservicechain and builds the logic description of service chain business process.(6) Pi calculus behavior equivalent theory is introducted to verify the accuracy ofservice chain requirement model that is whether the implementing result of servicechain is same to the users’requirement goal.(7) The implementing and management controlling methods of service chain isstudied, so that the execution engine has the functions of controlling the specificservices instance to be on the move and data transmissing. The engine is alsoresponsible for passing parameters, exception handling and interaction with the user.And it has the functions of managing and maintenancing service chain business model,service database registry center and service chain excution log etc.(8) The spatial information service chain building platform is designed andplemented to meet the application requirement of reginal spatial information sharingand serving. And taked the “Channel Logistice Public Information Platform”as thetypical application to verify the key technologies and methods of spatial informationservice chain in this paper.