Research On Demo Applications For Forest Spatial Data Platform Techniques

With the wide applications of geospatial information technologies including geographic information system, remote sensing and global positioning system, a large amount of forest spatial data have been collected and stored in forest inventory and management agencies and institutes. A number of forest business systems, forest information management systems and spatial databases have been established. Normally these systems run independently, and the methods of data structure and data formats are also different. Forest spatial data islands have been formed for lack of universal planning, coordination and interoperabilities. Forest spaptial data among agencies cannot be shared and integrated effectively. It is of greate significance to access and integrate heterogeneous forest spatial data from different sources.Fast development of computer technologies, especially the emergence of Web service techmology, provides potential capabilities to access and integrate heterogeneous forest spatial data from different sources. After analyzing the current status of forest spatial data sharing, comparing methods of heterogeneous spatial data sharing and interoperabilities, and further studying Web service technology, OGC Web Map Service, Web Feature Service, Web Cooverage Service and GML model, this paper proposes a Web service based forest spatial data platform framework. It can be a bridge between data providers and data users. The main contents of the thesis are as follows:(1) Reviewed the foundamental technologies related to sharing and integration of forest spatial data. The development of GIS architecture, implementation techniques of WebGIS and their advantages and shortcomings, the evolvement of spatial data management methods and internet markup languages were summarized.(2) Research on the key technologies related to construction of forest spatial data platform framework, including methods of sharing and integration of heterogeneous forest spatial data, Web service technology and its architecture, OGC Web service framework and data services specifications, and forest spatial data GML application schema.(3) Proposed a Web service based forest spatial data platform framework. The data network architecture of platform framework is of four level nodes: national, provincial, regional and county levels. Each node is responsible for its own data management, and data services are published and registered to the central data registration srver. Users can easily to find, access, and acquire data services to implement integration of heterogeneous forest spatial data.(4) Established forest spatial data servers compliant to OGC open specifications with open source software. The technical framework of each node is of three-tier: Web browsers or client application, data service server and data server. Two demo cases were studied: data service system for Shandong general remote sensing experiment area with open source software, and integration of forest spatial data and images in Google Earth. Case studies show that Web service based forest spatial data platform framework is attributed to access and integrate distributed forest data with different formats. Forest spatial data agencies at various levels can establish their own spatial data servers which are compliant to OGC open specifications, and join to the framework by publishing and registering their data services.