Research On Key Technologies For Transferring And Rending Of Global Spatial Data Base On Geography Spatial Information Grid

Mapping always is in the face of these problems since long time ago: The geographical information haven't been utilized enough; The GIS which be constituted by different departments can't be shared and worked; The global don't realize.The paper research the geographical information multi-level grid base on the earth's core reference and earth ellipse.lt can make the spatical information can satisfy the information ensure request.The research work include the following aspect:(1) Based on the advantage and disadvantage of equal space global grid data structure and spherical discrete grid system and characteristic of map projection, we bring formard a mix global data structure. Expatiated on the mode of grid coding and data storage and bring forward the method that converts the grid code to geographical coordinate.(2) Researching the theory, technology and method that convert the traditional data to geography information grid.We research the data's pretreatment, data's partition and data's conversion.(3) Researching the management of global geography data and introduce the data visit, update, and storage.We bring forward two persist storage unit, file and database.We bring the index scheme, so that the system can update the storage the data.(4) Further research the file manager system base on grid.Storaging data by machine group and satisfy the too many users visit.(5) Instead of traditional planar coordinate system, the GSRCS(Geodetic Spatial Rectangular Coordinate System) is used to render the earh is a real ellipsoid, not a preudo one. The system gets the data using multi-Thread and rends using GPU, uses the GPU and multi-core CPU to realize the real-time visualization of massive terrain data.The invariable frame technology make the system can run at invariable frame that satify the user's request.(6) Design and implement a prototype system named Global Geography Information System base on Grid.This system validate the correntness of geography information grid and data management and rendering technology, and bring forth experiment effect.