Research And Implementation On 3D Terrain Viewsheds Analyze And Displaying Technology

Analyzing and displaying geo-related information are the major functions in 3D GIS. 3D spatial analysis and operation for spatial object is important characteristic of 3D GIS, viewsheds analyze is part of it. The application of viewsheds analyze is as very broad as television tower the best location choice , radar station site and so on. Make use of 3D GIS to assist base station selections location, it can visually understand station site , coverage range, overlap region between sites coverage and so on. To make convenience for user to intuitively understand of the different sites location of the impact on communications, and be better on the mobile communication base station to carry out reasonable arrangements.Domain for viewsheds analyzing and the results displaying. The main content of paper: First of all, the real DEM data come into being three-dimensional terrain, and the generated three-dimensional terrain on texture mapping, enhanced realism, Such is realistic needing to reach the effect being personally on the scene at present.. The formation and display of three-dimensional terrain are the basis of all the work, all analysis and operation all are to come true on this platform.; And then, making use of picking up technology in Java 3D to get a viewpoint, reaching interactive with user. To obtain the observation point as the default location of the base station, making use of the algorithm based on reference planes to viewsheds analyze terrain. The algorithm is simple , no redundancy calculation and very fast computering speed. Third, displaying the result of viewsheds analyze is key of intuitively reflecting the communication base station coverage. Through constructing point set triangulation in viewsheds domain to formatting a new data model. Through adjusting data , colour and transparency and other parameters in displaying can reduce effect on 3D terrain ,Iandform displaying and later user interaction. At last, for increasing system interactive function, designs menu, toolbar, label, scrollbar and so on, the user can operate conveniently. Besides, this paper also achieve the function of surface area calculate and plane area calculate to be aimed at application needs.