Simulation Of Space Target Detection Based On3S Technology

3S technology makes rapid processing and display of geographic and spatial information come true through highly integrating of GPS(Globe Positioning System)、 GIS(Geographic Information System)、RS(Remote Sensing). In recent years,3D digital earth platform with high resolution and HD image data has been successfully set up and widely used in various fields with the rapid development of3S technology. In military applications, digital earth platform is usually used to construct a3D Geography Information Visualization System, through which the combat environment can be simulated and commanders can analyse the situation between enemy and ourself so to command more wisely. Compared to2D GIS, the3D-Geography Information Visualization System enables human to feel objective things more directly and truly, and observing the relationship of spatial location between different objects is convenient through it, so3D-Geography Information visualization has been a hot-spot issue and focus in the domain of research on computer graphics in recent years.There are lots of issues and key technologies to be studied in building3D-Geography Information Visualization System based on geography information data. This thesis mainly discusses the key technologies to set up digital earth platform、3D modeling and display technology、terrain viewshed analysis. Digital earth is the basic platform of3D-Geography Information System, and Obtaining and displaying the massive geographic and spatial data contained in it needs to be supported by various technologies. This thesis introduces several prevalent digital earth platforms and analyzes the developing trend of digital earth technology..3D modeling and display technology is used to construct all models contained in3D Visualization System and to realize their movement, this thesis introduces DirectX3D graphics library, studies the structure of3D models and their drawing process, and simulate the process of radar detecting. Terrain viewshed analysis, which means to analyse visibility of all points in detecting area, is theoretical basis of setting up3D model of radar detecting area. Because the scale of terrain raster data is huge, so the right algorithm should be used to analyse terrain viewshed. Several algorithms are compared in this thesis and Xdraw is used to get the minimum visual height matrix of radar detecting area.The two innovative points in this thesis are:(1)a radar detecting3D visualization system is developed based on digital earth platform, in which the3D detecting models of radars with different working system and parameter are constructed and displayed in digital earth, the movement of radar beam and spatial objects are simulated also. The cover situation of radar position is intuitively displayed in the system and radar detecting area in a specified altitude can be conveniently observed which can meet demand in real cases.(2) a novel method is presented to guard airline through radar network. For a certain airline across radar network, this method uses greedy algorithm to optimize the timetable of radar switch on and off, which can reduce the amount of radar on and off, and effectiveness of this method is verified through experiment.