Small Geographic Information System Platform Independent Research And Development,

This paper aims to make a research on CIS' s architecture and develop a small CIS platform whose intellectual property right is owned by the developers.The System adopts spatial data model based on the vector data model; topology relation model uses spatial data model combined with spatial data index; and makes use of relation database to save spatial entity data. UML technology is employed to design and layout the system structure. The object-oriented technology plies the Microsoft Visual C++ 6. 0 to develop the software. The spatial data index betakes the spatial data structure based on the improved R-Tree structure, and the property index uses the B+ tree data structure. Network data transportation adopts the three-level frame model, and uses Java Applet to exploit the network part.In the first stage of developping, the system performs good, and basic CIS functions, such as file operation, the conversion between different data formats, drawing vector graphics and query between spatial data and attribute data, can be realized with correct and rapid result and stability, however, to implement the whole functions needs a long period of hard work to develope the system to a deeper level.