一体化时空数据建模是新一代GIS理论与技术研究的重要基础。基于对象关系数据库探讨时空数据库的数据建模方法,提出综合考虑矢量和栅格数据一体化的时空数据模型。首先基于基本类型派生定义矢量和栅格抽象数据类型,在此基础上定义时空数据类型为一系列空间类型的时间片序列。该抽象数据类型的定义包括其数据对象和相关操作,将其嵌入对象关系数据库中,扩展其时空数据的存储和查询能力。利用该数据模型,可以统一考虑矢量和栅格数据,建立基于对象关系的时空数据库,并支持矢量—栅格一体化时空数据访问和操作,进而对新一代GIS技术的研究与实现起到重要支撑作用。
The integrated spatial-temporal data modeling lays the foundation for the next generation of GIS theory and technology. Based on ORDBMS,a spatial-temporal data modeling method is presented, which can integrate both vector and raster data. The abstract data model (ADT) of spatial data, vector and raster, is defined firstly based on basic types. Then the spatlal-temporal data model is defined as a series of temporal slices of spatial ADT, which includes both data objects and functions. When it is integrated into ORDBMS, this model can access vector data and raster data with the same interface,and then can extend ORDBMS to support spatial-temporal data storage and spatial-temporal data query.