Research On Geospatial Services Aggregation For Common Platform Of Geography Information In Digital City

Based on geospatial data, the Common Platform of Geography Information(CPGI) in Digital City aim to meet the basic demand of geospatial information for government, enterprises and institutions.At the same time, CPGI should support personalized API andthe expansion of space.In the CPGI,geospatial data and processingfunctions are released to the network in the form of Geospatial WebService(GWS).And the GWS provides the call interface to the outside world, so that any platform, any system and any program can call the services.Therefore, the GWS is cross-platform and strongly scalable.It can be said that the emergence and development of GWS solve the problems of the geographic information sharing and interoperability for common platform of geographic information effectively. With the construction of CPGI, it is an important pattern of using spatial information to dynamically integrate the various existent GWSs to form a newly value-added and complex GWS,so the technology of composition of GWSs is to be a new pop research area in the field of spatial information.This paper refers the existing geographical information standards of CPGI.On the basis, we discuss thestructure and classification system of geospatial service for CPGI in digital city. In addition, we analyze the existing technology and methods of geospatial service aggregation and then focuses on the suitable service description and discovery methods for common platform of geographic information. Ultimately, we design the finite state machine for RESTful services for executing geospatial service aggregation.Works done in this paper are as follows:Firstly, wedesign the architecture of RESTful geospatial service and classification system for common platform of geographic information in digital city.and analyze the existing techniques of geospatial service aggregation.Secondly, according to the current problem of geospatial metadata, this paper proposes metadata standard for RESTful geospatial services based on the expansion of existing geospatial metadata standardand match geospatial services efficiently and accurately using the appropriate method of service discovery according to the different characteristics of geospatial processing services and data services.Thirdly, express the process of RESTful geospatial service aggregation using the workflow of RESTful service in the paper.Moreover, based on the traditional finite state machine, we propose themodel of finite state machine for RESTful geospatial service(RFSM) by expanding the traditional finite state machine, and to execute the process of service aggregation for RESTful geospatial serviceusing RFSM in CPGI.Fourthly, we design the architecture of prototype system for RESTful geospatial service aggregation based on the research results of this article.Achieve the registration and discovery of RESTful geospatial service.