Three-Dimensional Modeling Of Space Radio Business

With the development of satellite communication science and technology, more and more countries have recognized the important strategic significance of satellite frequency and track resources to politics and national defense building. At present, the satellite frequency and track resources have become the essential resource to every country. So, how to make good use of the limited satellite frequency and track resources, and how to protect and preserve our country's legitimate rights at the greatest extent have become the radio management authority's principal mission. The three-dimensional space radio business demonstration system designed in this paper simulates the real three-dimensional space radio business by computer three-dimensional simulation and three-dimensional GIS, and it has become a powerful tool for studying the planning and development trends of satellite frequency and track resources and analyzing satellite business to the radio management authority.The system will show the states of satellite running around the earth, orbital plane, beam, link circuit, relevant ground radio station in the way of making simulation graphics at screen, and it vividly shows the state of space business communications systems at home and abroad, helps the management and staff to understand the substance of the space business, master the situation planning and using of the satellite frequency and track resources, provides auxiliary support functions to scientific management, rational exploitation and effective use of the satellite frequency and track resources.System software development uses Microsoft.NET and Microsoft D3D as support, uses model data and presentation analysis separation model, takes ITU (International Telegraph Union) and country space business data as object, uniforms data interface standard, complete the analysis of the space radio business management work, simulation analysis the space radio business communication system at GIS platform. Focus on the three-dimensional presentation platform module, database management module, and database design and implementation. About the three-dimensional space design, we have adopted the multi-level zoom mode, and took the three-dimensional GIS technology combined with the existing two-dimensional GIS graphics layers, provided real and effective simulation environment for the system software; about the database and data structure design, we took variety of heterogeneous existing business space data unified to the same data model, ensure data integrity and timeliness, uniform data interface standard, realize the space radio business analysis and management.About the three-dimensional space implementation, we take the most effective DirectX3D three-dimensional engine under the Windows operating system platform to simulate 3D space, maximize the use of own display card's three-dimensional computational performance, improve the three-dimensional computational speed and displayed effect. We took technology of three-dimensional texture to simulate the geographical situation of the surface of ups and downs. The geographical data of the surface of ups and downs generates from the real world elevation data, based on latitude and longitude coordinates data of elevation data and satellite images, manage two-dimensional satellite images into the convexity of real three-dimensional texture image. We use surface information marked by GIS data of two-dimensional graphics layers, included the surface topography information and humanities information. These information stored in the form of documents, and could carry out real-time updates. Take the strategy of the three-dimensional GIS texture combined with two-dimensional GIS graphics layers data. Two-dimensional GIS data includes height data, latitude and longitude data, administrative area data divide and so on, but satellite picture is true surface image, and the effect is visual and clear. It take the three-dimensional satellite picture to overlay special GIS raster and vector data overlay, realize the real three-dimensional surface topography effects. Because three-dimensional texture is a three-dimensional graphics, but two-dimensional GIS layer is a two-dimensional data, when fitting the two kinds of graphics layers based on latitude and longitude coordinates, three-dimensional platform will also convert the two-dimensional GIS graphics layer to three-dimensional GIS graphics layer in accordance with elevation data, so three-dimensional texture and two-dimensional graphics layer realized Seamless integration. About data structure design and database management, because there are a lot of data source, such as orbit satellite data, coordinated satellite data, ITU annual report data, ITU weekly report data, national space business data, station data, spectral data and so on, we created a unified database and common data interface, these data will be generated into a unified system, so we can analyze and manage the space communication business comprehensively and effectively.About satellite data model and space background model design, for the calculation of location of the satellite orbit, based on Kepler's Third Law, adopted the American air defense joint command SGP4 space orbit prediction model to simulate and analyze satellite movement trajectory and rate, improved the accuracy of simulation; for the computation of location of sun and moon, because of the movement of sun and moon affected by other planet, especially the moon's movement is affected by not only the earth and the sun but also other plants, when computing the mathematical model of the location of sun and moon, we consider combining available information with the methods suggested by authority of international organizations.This paper introduces the study background, system design and implementation of the three-dimensional space radio business system, focus on the platform of three-dimensional demonstration and data management module。The whole paper consists of four parts: the first part includes chapter one and chapter two, mainly introduced the development of the background of the system and related technologies involved; the second part contains chapters three and four, introduced the system architecture design and data flow design, data management; chapter five as the third part of the paper, detailed introduced the thinking of design of three-dimensional demonstration platform and specific implement ways.The first part introduces the research background of this subject and the current status of the current space radio business research, deficiency of current space radio research, so put forward the need for the system, then introduced the work that the system will complete, as well as the difficulties encountered and the corresponding solutions in the system development process, at last, the relevant technical background of the system is introduced.The second part, at the first, states the specific system design principles, next it specify the composition of the concrete structure and give the system structure graph; module-level structural design, at first, we gave the module-level structure chart as well as specific description of the relationship between the levels, and then given a detailed flow chart of the data and Instructions, listed the data interface used; list all the relationship between the major business model table, then introduced the data structure design, data files includes project model file, document of three-dimensional model definition, graphic layers data file and so on. At last, this part introduces strategy of data management.The third part mainly includes modular design of three-dimensional presentation platform, specifically introduce the technology solutions strategy of three-dimensional demonstration. At first, this part introduces the design of three-dimensional model of GIS, separately introduce the earth texture and strategy of fitting graphics. Then, there introduces the three-dimensional model of the space environment design, and give the detailed design of every model, in this part it focus on model of the sun and moon design. At last, this part stats design strategy of space satellite and station group, satellite design includes geostationary satellite design and non-geostationary satellite design.