A Research Of Model,Arithmetic And Transmission Techniques In Mobile Geospatial Information Service

Mobile Geospatial Information Service refers to provide geospatial information for mobile persons. The dissertation is centered on geospatial information service model, architecture, geospatial data streaming transmission, and geospatial media streaming server design in mobile geospatial information service system. Finally, a prototype system has been designed and realized. The main work and originalities of this thesis are as follows:1. Mobile geospatial information communication model and geospatial cognization model are presented based on the analysis of map communication model. Mobile geospatial information service system's architecture is designed based on these two models.2. The conception and method of streaming transmission of geospatial data for wireless transimission is proposed. The principle of the streaming transmission of geospatial data is introduced. A new geospatial data transmission protocol is proposed based on the analysis of internet protocol.3. Delaunay triangulation is introduced into scalable coding methods for point feature data. A scalable coding method of point features is presented based on progressive simplification of TIN. The experiment shows it an algorithm of good performance and which is easy for data storage and transmission.4. Scalable coding method for contoure feature data is researched. A scalable coding method of contoure features is presented based on progressive coding of TIN. The method looks on all contour features as a whole, so it has good performance for progressive transmission and no intersected contoure features appear when the code stream is decoded.5. Scalable coding method for other vector data is researched. A semi-scalable coding method for other vector data is discussed based on tile-grade and taxis. The experiments show it a method of better performance than directly tiled data transmission.6. Architecture of the streaming spatial data server system is proposed based on the analysis of massive storage system and distributed parallel architecture. And the declustering methods and grid spatial index in dada management are introduced.7. Data cache technology is researched. A plus model of storage server in streaming spatial data server is proposed. Based on the model, the cache replace method is discussed.8. Finally, a prototype of mobile geospatial information service system is developed based on the research work of the thesis. Experimental results show that the prototype system can manage massive streaming geospatial data, supports streaming stransmission.