Research On Geo-Spatial Information Grid And Application In Continuously Operating REference Stations

Grid is the internet basement infrastructure aiming at resource sharing, which has developed quickly in the 21st century. It connects high speed internet, high performance computers, databases and sensors together, builds up open and service-oriented architecture, integrates information- Island to information-continent, and provides one-click-enough service and on-demand service for users. The resource of Grid includes computer, network, software, data, and information, knowledge, computing capability, storage capability and human resource. The key of resource sharing depends on internetworking, interconnecting and interoperation.It is inevitability to apply Grid and its resource sharing technology in Geo-Science to set up Geo-spatial Information Grid (GSIG). Recently, the amalgamation of geo-spatial information technique and network technique forms network real-time kinematics (NETRTK), WebGIS and some new techniques demonstrate such characteristics of the universality of technology integration and service, the integration of system and service and the phase of technical development ,etc. That will lead to the development of GSIG.The GSIG is a set of interconnected geo-spatial information capabilities, associated processes and personnel for collecting, processing, storing, disseminating and managing geo-spatial information. It provides one-click-enough service and on -demand service for users. Continuously Operating Reference Stations (CORS) is the important component of GSIG.CORS is the infrastructure based on network and GNSS. It can provide the service of positioning, coordinate datum information, etc... Recently, several problems need to be solved in CORS: internetworking, interconnection and interoperation. The goal is information resource sharing, Grid and its resource sharing technology to realize give a solution of that problem.This dissertation has researched on the Grid deeply and systematically, summarized the technology and method of the resource sharing in Grid. On that basis, this dissertation put forward the GSIG architecture and service and the solution of CORS internetworking, interconnection and interoperation. On the basis of GSIG architecture, the CORS network architecture is proposed for the first time, and the concepts of Quality of Service for CORS (CORS QoS), network reliability design for CORS are proposed. Accordingly, the distributed system architecture for CORS is proposed for the first time.Focusing on GSIG and CORS, the main works done in this dissertation are as follows:1. The dissertation focuses on the concept of Grid, grid service and architecture. Theservice-oriented architecture, virtual originations and grid fabric virtuality has been discussed. On the basis of the research of Grid sandglass model and Open Grid Service Architecture (OGSA), and the Global Information Grid (GIG), the dissertation summarized that the uniform architecture framework of the system is one of the techniques of the system interoperation improvement.2. This dissertation discussed on the concept of GSIG and its architectures based on the Grid research. The GSIG is a set of interconnected geo-spatial information capabilities, associated processes and personnel for collecting, processing, storing, disseminating and managing geo-spatial information. GSIG can provide geo-spatial information service for users as one-click-enough and on-demand. The GSIG architecture is consisted of five layers: foundation, communications, computing, application and user. Its service is the domain services and composed of basic service and advance service. The basic service includes: space positioning, space attribution, space relationship, time, raw data and coordinate datum information. It is the basic geo-spatial information service.3. Based on the concepts of GSIG, this dissertation summarized the concept of CORS, the service of CORS and system structure, etc... It pointed out that the CORS is the important component of GSIG. CORS can provide coordinates datum information, post-positioning, raw data and time service. It can be divided into regional, professional and national system; it can also be divided into static and real time system. CORS is composed of reference stations, system center and user item.4. The CORS network architecture is proposed in this dissertation for the first time. CORS network architecture can be divided into three layers: communication layer overlay layer and application layer. Every layer can form a network with different meanings. On the basis of the architecture, the CORS protocols cluster is proposed, which is composed of communication protocol, application protocol, management protocol and quality of service protocol.5. The concept of CORS QoS and its hierarchical structure are set up for the first time in this dissertation. CORS QoS is the precision mechanism and measure which improves systematic reliability, usability integrality and precision of positioning, in order to guarantee satisfaction required to service. CORS QoS is made up of IP QoS and applicational QoS. The criterion of application is proposed in this dissertation also.6. This dissertation researched on the structure and feature of CORS overlay network. On the basis of the graph theory algorithm, the structure algorithm of CORS overlay network is proposed. The CORS overlay network is composed of star network and random network,and it is a kind of scale-free network.7. This dissertation summarized the network reliability design for CORS and gave the main criteria. The criteria includes: The quantity of reference stations of urban CORS is 4 at least. The connection between the reference station and the system center should be Client/Server(C/S) and Peer to Peer (P2P). In CORS system, GNSS positioning technique with far distance should be adopted as main service means, and other GNSS positioning techniques as backup means. Advanced central node should establish the sharing relation with at least 60% of the low-level center/core node within that area. Grid is formed with regional and urban centers.8. On the basis of CORS network architecture, the distributed system architecture for CORS is proposed for the first time. This dissertation analyzes the component of CORS software system. It pointed out that the software includes communication layer software overlay layer software and applicational software. Overlay layer software is named as CORS middle-ware.9. Based on the CORS distributed system architecture, the dissertation works out the class library of CORS middle-ware under NET frame using C#. This dissertation developed system management software and reference station management software under Windows using the class library, and put into practical application in several projects.10. This dissertation summarized the content of CORS system design. And pointed out that system design must carry on two fields: network design and project design. The CORS network design includes network topographic design and CORS QoS arguments design. The project design includes system structure design and hardware software design.11. The dissertation summarized the test items and method of CORS, and pointed out that test must be carried out in positioning precision, usability and service time-efficiency. The usability depends on space and time.