Design And Lmplementation Of Space Situation Visualization System Based On Open GL

The number of on-orbit space objects has been growing continuously because of the rapid development of aerospace industry, collision risk between space objects also increases significantly, which has been strongly threatening the normal running operation of the spacecraft and the development of aerospace industry. Human beings must strengthen the study of space security problem. Mastering space running situation is one of the key parts of studying space security problem.As the development of computer simulation technology, visual simulation technology is heavily employed in the design and application of aerospace product. Visualizing objects orbit data in 3D using OpenGL visual simulation technology will help the understanding of objects running posture and orbital characteristics.Firstly, space objects orbit dynamics model is studied. The common used time system and coordinate system in orbit dynamics simulation are introduced; two bodies orbit prediction model and SGP4/SDP4 analytic orbit model are given; geometric coverage scope of satellite is analyzed.Secondly, visual simulation technology in space situation visualization system is introduced. the working principle of OpenGL and the model transform, view transform, projection transform and viewport transform from 3D space to the 2D screen in OpenGL are described; OpenGL texture mapping techniques including one-dimensional texture mapping, two-dimensional texture mapping and cube texture mapping are expounded; 3DS format model loading and rendering methods and three-dimensional model management method based on the XML file are proposed; space objects pickup algorithm based on two-dimensional image is deduced; effects display techniques including the Earth’s atmosphere simulation, lighting effects and sky celestial background in space situation visualization system are introduced.Then, scene control technology in this system is considered. Viewpoint transform in spherical coordinates and viewpoint translation, rotation and scaling transform algorithm in the corresponding spherical coordinates of screen coordinate transform are deduced; scene roaming method based on the path roam and collision detection problem in the process of the scene roam are analyzed.Finally, main components of system are elaborated from functional requirements, design constraints and development environment; system hierarchy and composition are analyzed; external file interface and internal data interface are described; MFC-based space situation visualization system using Visual C + + 6.0 and OpenGL development libraries is built. This system is user-friendly, with strong interactive features.