一种平面移动对象的时空数据模型

提出了一种平面移动对象的时空数据模型--OPH模型.在该模型中,平面移动对象由3种几何表示,即平面对象的观测几何O,目前存在的几何P以及平面移动对象的历史几何H.通过几何点集的差、并、交,研究并得出OPH的递归计算和更新策略.通过分析对象之间的空间拓扑关系和时间关系,得出两个平面移动对象在重叠时间区间上的时空拓扑关系.利用OPH模型,定义了平面移动对象的速度、方向、影响范围等空间方法;利用时空拓扑关系和空间方法,确定时空查询和空间触发事件.

A Spatial-Temporal Data Model for Moving Area Objects

A spatial-temporal data model, named OPH model, for moving area object is presented, which considers spatial distribution and temporal evolvement of the moving object. In this model, the feature geometry of moving area object described by three kinds of spatial-temporal geometries, which are observation geometry, named O; currently present geometry, named P; and history geometry, named H. The definition of OPH is given, and then by using the union, the intersection, and the difference of set theory to populate the value of O,Pand H is populated and calculated.The spatial-temporal topological relation is defined between moving area objects,then three spatial temporal operators based on OPH,Speed,Direction and Range of moving object,are given,and the examples of spatial-temporal query and trigger based on OPH are provided.