| It is the development of the deep-application of GIS and the drawing of correlative technology that pushes GIS forward. The super and multidimensional characteristic of the informational battle and the actual needs of the modern joint operations have put forward some new demands on GIS. The traditional mode which looks on map sheet as applied unit has not contented with practical application. Therefore, this paper proposes a new notion, namely seamless GIS, try to analyze and design in theory and practice, and manage to provide helpful reference for solving this question.This paper expounds the concept of seamless GIS, designs the data organization and the structure about it, builds the conceptual framework on it, and researches some correlative algorithms and applications. The main content of this paper are as follows:(1) The basic concept and academic framework of seamless GIS are established, the function, content, process and the distinction between seamless GIS and conventional GIS are perfectly expounded. This paper also points out that the function of seamless GIS is carried out by means of seamless spatial data cooperated with GIS software platform.(2) Spatial data organization and structure of seamless GIS are studied principally. This paper put forward a kind of innovative data organization and correlative merging access means, which are based on tile and attribute merge table faced to whole feature entity, this will ensure that the data memory is block in physical and is continuous in logical. In this paper spatial data organization structure chart of seamless GIS is advanced, the point, line, area, complex feature, DTM data and attribute merge table of block are discussed in detail.(3) The input mode of multi-format and multi-scale data of seamless GIS are studied. This paper brought forward a new method which is used to solve multi_source spatial data seamless integrate by making use of data intermediate technology in the first place. The input method of multi-scale data and three levels data index are investigated, a new own idea about how to represent multi-scale seamless data is advanced. The viewpoints that seamless GIS is looked on surface of globe reference ellipsoid as spatial information positioning standard and looked on geographic coordinates as reference of spatial data storage are explored, and based on reference ellipsoid surface coordinate, the measurement model of distance, azimuth angle and area are given.(4) The flowchart of data production of seamless GIS is analyzed, on the basis of the program algorithm and the interactive processing of feature adjoining relation, the data production method of seamless GIS is discussed. Seamless GIS data production method of linear feature and areal feature is introduced primarily, the plan of annotation layout of seamless data is designed, and annotation data structure is set forward too.(5) Comprehensive functional structural diagram of seamless GIS is described, some processes and functions are introduced, these progresses and functions includes data display, graphic auxiliary operation(zoom and pan), symbolization, query of spatial, geographical name query and structured query language, three-dimensional visualization display. The specialgraphic output device of seamless GIS-large screen joint display is introduced, andfunctional effect graph is set forth.Keywords: Seamless GIS, Conceptual Framework, Multi_Source Data Integration. Tile, Middleware Technology, Logical Seamless, Data Production, Attribute Merge Table, Clipping, Attribute Correlation.
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