The Research On The Sharing Of Multi-source Heterogeneous Forest Resources Data

Forest resources data is various data which obtain through forest resources survey, monitoring and management, and it is the base of a variety of forestry information system. This is a great challenge for people to sharing, exchange and joint work of the application of forest resources data,because that so differences of data sources is in system platforms, data standards, data structure and storage, and the data is more widely distributed.Multi-source heterogeneous data-sharing of forest resources has become a research hotspot.In order to resolve the problem that multi-source heterogeneous data sharing of forest resources,this paper put forward a based on grid service-oriented multi-middleware system.The main research results are as follows:(1)Putting forward a based on grid service-oriented multi-middleware system. Multi-middleware system includes resources layer, grid operating environment layer, grid services layer, forest resource data application service layer and application layer. Data middleware is a part of grid operating environment layer, which makes multi-source heterogeneous data standardization, and implement multi-source heterogeneous data sharing of forest resources.Based on service-oriented, the forest resource data application services layer (services middleware layer) is determined by a series of data on forest resources for different application services.(2)Expaned the OGSA-DAI,design the data middleware based on the WSRF standars.The four-tier structure for the data middleware:data layer, Business Logic layer, expression layer and the client.Data middleware accomplishs data resources interactive services and the data flowing of the client and data resources by the documentation interface;data milleware make standardization of table data,data structure and coding, in order to implement multi-source heterogeneous standardization sharing of forest resources data.(3)Designed services middleware layer based on Web services technology. The services middleware layer has data common services, data resources packaging services and forest resources data applications services. The forest resources data applications services can implement different services for the forest resource data different application requires.Data common services focus on the design of data processing type;The data resources packaging services package the data which have been standardization by the data middleware,and register data or update data to gird information services.(4)Using middleware validate forest resources data which have different data formats.For different data sources types,the different GDS will used to access spatial data; Integrating spatial data which is coming from the different GDS and described by GML document, and provided this GML document to clients,and implemented the spatial data sharing. Multi-middleware systems as a geographical information SVG format, When GML documents are converted to SVG documents, the spatial data will display.