导航应用需要动态多尺度路网数据的支持。描述交通特征的时空多尺度语义,利用象形符号扩展的UML表示法,设计适用于导航的动态多尺度路网数据模型。模型以车行道为拓扑数据建模的基本单元,以完整道路为几何数据建模的基本单元,实现路网拓扑/几何的分离与多尺度表达,以及交通状态、交通事件、统计行程时间等动态信息与路网的集成表达。试验表明,本文提出的模型为相应的数据结构设计与数据库实现奠定了良好的基础,能有效支持导航应用。
The transportation feature was described in three domains:theme,space and time,and a conceptual dynamic multi-scale road network data model for navigation was then designed with spatial,temporal and scale pictograms enabled UML class diagrams.It separated the topology and geometry of the road network,modeled the geometric network based on roads,and modeled the topologic network based on carriageways.These two networks were organized into hierarchical levels in terms of different criteria,namely,road class for the topologic network and display class for the geometric network.Different kinds of dynamic information,including traffic status data,traffic event data,statistical travel time data,etc,were integrated with the underpinned road network by link-node linear referencing systems and time-dependent thematic attributes.The experiment showed that the proposed model is effective in favoring the design and implementation of the corresponding data structures.