| Nowadays, the research and development of geographic information system (GIS-T) attracts more and more the attention of scholars and traffic managers as the urban city problem gets worsen. In recent years, most of GIS are still belonged to the static temp GIS yet. With little consideration of the dynamic traffic information, they are lack of support for temporal feature of the traffic data, and unable to meet the needs of the discrimination of network traffic status, the forecast of transportation development and analysis of road management and so on. Therefore, it is necessary to study dynamic traffic information temporal data model.According to the characteristics of linear distribution and real-time change of traffic status, one kind of dynamic traffic information, this paper attempts to establish a sequent snapshots concept model of traffic Status based on dynamic segmentation technique. Then its spatial-temporal database is built too. Finally, this model is employed in the design and development of corresponding GIS system, with further examination for this model being conducted.The main contributions of this thesis are as follows:The automatic vectorization of raster traffic status images. The numerous experiments of online traffic status raster data sums up a method of vectorization of raster traffic status data by using the dynamic segmentation technique, which consider the road network as linear referencing datum. And the traffic status event table is available at the same time.The spatial-temporal modeling of traffic status data. Through the analysis and comparison of several spatial-temporal data model, this thesis designs and builds a sequent snapshots conceptual model of traffic Status based on dynamic segmentation technique. It takes the traffic status event table as a time snapshot to represent the current traffic state of the entire road network, rather than the traditional form of raster or vector data. Then its corresponding spatial-temporal database is provided and design based on SQL Server2008database.The design and development of application systems. In this research, an experimental system of Chengdu traffic status information is implemented with C#based on ArcGIS Engine. This system realizes visual query analysis of traffic status based on spatiotemporal database designed above as well as its download and vectorization. |
