Research And Implementation Of Real-time Visual Simulation System Of In-orbit Satellite Movement

"The visual simulation system of satellite motion in orbit"is an integration environment of orbit design, orbit simulation and visualization, which combine the theory of orbit simulation with computer graphics technique. The system can give user plentiful and visually result of simulation; consequently help them accomplish the design, validation, argumentation, filter and decision of flight scheme. This paper analyzes some key technologies about geometric modeling, kinematics modeling, model driving and displaying. Based on the three-dimensional real-time display technology the visual simulation system is developed to simulate attitude and orbit of satellites. Firstly, some optimum technologies about geometric model are introduced; According to the earth model we expatiate on entire sphere texture mapping and half sphere texture mapping. The realistic earth is modeled by using entire sphere texture mapping. Secondly, this paper discusses in detail the basic law and equations of the orbit dynamics, and then deduces the formulas for calculating the spacecraft's position and velocity in several main coordinates; In order to make use of the exiting program about orbit calculation of satellites which is written in Fortran, Mixed-languages programming (Fortran and VC++) is realized by using DLL. Thirdly, after geometric modeling and kinematics modeling, the virtual scene is driven. This paper analyses VC thread and Vega thread in the simulation drivers. For Vega window thread can't be terminated, presents multi-processes to develop Vega application. Because some functions cannot be realized in Vega, such as contrail displaying and Chinese characters displaying, this paper presents the integration of Vega and OpenGL. Moreover, a multi-viewpoint, multi-angle, omnidirectional observation method is presented. Finally, This paper describes the design and implementation of visual simulation, based on software platform-MultiGen Creator and Vega, the visual simulation system of satellite motion in orbit is developed.