Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer based model to represent geographic information in the existent GIS. However, it is diffic...Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer based model. Furthermore, in Web Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale based model. In this model we represent maps in three levels: scale view, block, and spatial object, and organize the maps in a set of map layers, named Scale View, which associates some given scales. Lastly, a prototype Web Based GIS using the proposed spatial data representation is described briefly.展开更多
文摘Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer based model. Furthermore, in Web Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale based model. In this model we represent maps in three levels: scale view, block, and spatial object, and organize the maps in a set of map layers, named Scale View, which associates some given scales. Lastly, a prototype Web Based GIS using the proposed spatial data representation is described briefly.
