Design And Implementation, Commonly Used Geodetic Coordinate System Conversion

Due to historical reasons, different countries and regions, the use of different reference ellipsoid, and thus there will be a different geodetic coordinate system; the same country or region in different historical periods, for some reason changed the reference ellipsoid, there will be different geodetic coordinate system. China is currently used mainly three types of geodetic coordinate system, according to the selected reference coordinate origin can be divided into the heart coordinate system, geocentric coordinate system, independent local coordinate system. Each of these three types of coordinate systems and the use of a particular target range, and only through a detailed understanding of the ellipsoidal coordinate system parameters, characteristics and applications, each turn of their mathematical model of change, including the coordinate system conversion of model selection , benchmark selection, method selection and parameter choice, in order to better serve the development of China's surveying and mapping services, so as to make due contribution to the national economic construction.Papers from the establishment of the coordinate system needs to discuss the development of China's popular overview of coordinate systems, the choice of the Earth ellipsoid, coordinate system used to establish the principle, the establishment process, and their comparison, analysis and research, including the ellipsoid parameters characteristics of the base conversion, the conversion parameter selection problem.Second, research and coordinate system conversion count and for positive and negative Gaussian with a computing concepts and the main conversion process and conversion formulas. From the theoretical analysis of our common coordinate system conversion principles and processes. Include a reference coordinate system and the heart of the earth geocentric coordinate system and spatial coordinates between Cartesian coordinate system conversion, space between the Cartesian coordinate system conversion, computer and change with positive and negative Gaussian calculation. Coordinate transformation theory of in-depth research, follow-up paper work to lay a solid theoretical foundation, provides a coordinate system related to the preparation of the application software must convert the formulas and methods and the establishment of a common coordinate system transformation between the mathematical model.Again, the analysis software used by XP, VC and application platform, based on software developed by the basic requirements and needs are analyzed and discussed, mainly from the user-friendly, easy to use, real-time requirements and practicality combining and shall meet the overall system functional requirements and system accuracy. On this basis, the design of the system on the overall structure and main function modules, including the space between Cartesian and geodetic coordinate conversion module, the different spatial Cartesian coordinate system conversion module, calculation module and the adjacent positive and negative Gaussian with a coordinate conversion module, to use the final development of the common geodetic coordinate system conversion software, has the following main functions: to achieve common geodetic coordinates transformation (mainly earth and space coordinate conversion between Cartesian coordinate system), common ground coordinate system (mainly different spatial transformation between the Cartesian coordinate system), and count change with positive and negative Gaussian calculationFinally, the software developed for the feature presentation, examples and comparative analysis of test data, results show that the thesis developed powerful software, coordinate conversion accuracy and reliable.