3DGIS中基于改进R树的空间索引技术研究

A Study of Spatial Index Techniques Based on Improved R-Tree in 3DGIS

空间索引是GIS的重要技术之一。3DG1S作为新一代GIS技术的重要分支,其数据管理技术较二维地理信息系统复杂,迫切需要引入适应3DGIS环境的三维空间索引技术。作为一种高效的多维索引技术,R树及其变种已在二维地理信息系统中得到广泛应用。针对3DGIS的特点,通过改进R树的部分算法,和修改R树的数据结构,本文给出了一种适宜3DGIS数据管理的改进R树索引方法。基于三维地理信息系统平台GeoView3D开发的实例证明,改进R树索引较传统R树索引具有同层节点重叠率低,空间利用合理,空间操作快的优点,可以满足3DGIS中大场景数据的显示和查询等操作。

Spatial index techniques are important in geographic information system. As an important branch of new GIS technology, 3DGIS is more complicated than 2DGIS in data management, and so spatial index techniques are needed urgently. The R-Tree index and its variations are used widely in 2DGIS as an efficient multi-dimensional index method. An improved R-Tree index for data management of 3DGIS has been constructed, after improving partial algorithms of R-Tree and the data structure of R-Tree. Based on the experiments operated on the GeoView3D, it has proved that the improved R-Tree has the superiority of lowering overlap rate in the same layer node, making reasonable use of spatial room, and running more quickly in spatial operation, which can be satisfied with displaying and querying data of large-scale terrain in 3DGIS.