Study On Key Technologies Of 3D GIS Port Monitoring System

There are lots of cargo ships and transport vehicles out and in ports in modern times, with containers throughput in the tens of thousands. It is of great need to carry out real-time monitoring of ports' operating and information requiring through scientific and effective management systems. According to the features of Port 3D GIS Monitoring System, we concentrate on key problems, such as the predigesting modeling and rendering of surrounding terrain environment, the trail line simulation of vehicles and fast rendering of groups of containers. We explore the modeling and rendering of the multi-regional multi-resolution terrain mesh model, the vehicle trail simulation technologies based on spline curves, as well as model instancing based on the GPU rendering technology. We also design and realize a system for Port 3D GIS Monitoring with related technologies and algorithms.With the rapid development of the informationization construction of the armed police, all kinds of combat duty database management systems have been established. "The information spatialization" has already become an urgent need of combat duty information management. Through the research and realization of 3D GIS Port Monitoring System, the concept of the design and application of 3D GIS Monitoring System for the armed police force is proposed.The main work stated in this thesis focuses in the following aspects.1. Modeling and rendering technology of surrounding terrain environment. Accoding to characteristics of ports basic terrain environment, an effective technology of terrain modeling and rendering is proposed. We segment the mass terrain data into parts, and establish subregional multi-level TIN LOD models based on the model predigesting rule of polygon vertex normals. We also pre-culling data for rendering using viewpoit parameters, which enhance the efficiency of rendering further.2. Vehicle trail simulation method based on spline curves. Cardinal spline function is used to construct spline curves with four consecutive orientation information as the controlling points. The positioning data are interpolated with simulation time as the interpolation factors, which leads to very realistic simulation results.3. Model instancing based on the GPU rendering technology. An efficient technology for geometry instancing based on vertex texture fetch. Containers geometry texture coordinates information and the spatial distribution information of instances is packed into an vertex texture, with geometry vertex encoded, which not only brings rendering data to a minimum, but also reduce the number of the changing of rendering states and the calling of functions and batches.4. The framework of 3D GIS port monitoring system is designed, as well as the system's main functions being realized. Some key technologies which are involved in the process of realization are also studied.5. Based on the needs of the informationization construction of the armed police, special requests to 3D GIS monitoring system in the army are analyzed, and thoughts has been carried on the content and the application patterns of 3D GIS Monitoring System for the armed police force.