Research On The Construction Of Geographic Spatial Information Multi-grid

Geographic Spatial Information Grid,which combines the grid and the spatial information technology,is expected to be the domestic and foreign innovative hotspots in acquisition,processing, sharing and service of the geographic information data,as a result of its important strategic significance and its broad application prospects.The construction of Spatial Information Multi-Grid is the theoretical basis as well as key technology for the research on the structure,organization,expression and retrieval of the global geospatial data.The main contents of this paper are listed as follows:1.The analysis on some typical grid division methods of Geographic Information Grid at home and abroad.Firstly,it briefly introduces the history of grid.Then,the city kilometer grid based on plane,the Military Grid Reference System(MGRS),the global discrete grid based on Parallel plane projection,meridian and parallel grid based on ellipsoid(sphere),and the establishment of regular polyhedron grid are analyzed one by one.2.The construction of Geographic Spatial Information.Based on the status and characteristics of national spatial data,the basic principles of national Geographic Spatial Information Multi-Grid construction is expounded.After that,the global meridian and parallel grid division methods are put forward as follows:the division and encoding schemes based on 6°×4°,6°×6°meridian and parallel;the 6°×6°meridian and parallel division method and encoding schemes based on area threshold.3.The selection and design of the global map projection under the grid environment.The paper selects and designs some kinds of map projections,including the rectangular cylindrical projection, the perspective cylindrical map projection,the azimuthal projection and the combination of them.All of the above projections fit in with the Geographic Spatial Information Multi-Grid, facing the construction of global dynamic data model and making for the integrated earth display.4.The establishment of the experimental system.The VC++ platform and the OpenGL technologies are used for the experimental system so that the multi-grid division,the grid transcoding, the global LOD and the validation and visualization expressions of the integrated global projection can be implemented in it.In a word,the significant exploration and innovation of this paper lies on both the division and encoding schemes of the Geographic Spatial Information Multi-Grid and the selection and design of the global projection.The fruit in the research acts as a guide beneficial to the construction of national Geographic Information Grid.