Analysis And Research Of Coordinate Transformation Algorithm And Model Error

The main job of mapping is to locate a point in space, and therefore requires a parameter to express the spatial position of the point. Mapping the main parameters for spatial coordinates Cartesian coordinates (X, Y, Z), Cartesian coordinates (X, Y, H) and geodetic coordinates (B, L, H). In engineering practice, what we using more is Cartesian coordinate plane and geodetic coordinates. For the study of the theory and model representation of the coordinate system, using a three-dimensional Cartesian coordinates ideal.With the development of spatial positioning technology, GPS mapping technology used in the field, GPS measurements using the WGS-84 coordinate system, and the existing national coordinate our benchmarks are:Beijing 54 coordinates, Xi’an 80 coordinates, the 2000 national geodetic coordinates. They often use a separate coordinate measurement and engineering survey in the city, such as:coordinate urban construction, highway, railway, hydropower construction projects independent coordinates. In the application process due to different purposes using different coordinate systems of coordinates, so is bound to face each other to convert coordinates between different forms of the same base and coordinates between different coordinate systems issues. Coordinate conversion precision engineering applications directly affect the topographic map of measurement, control all aspects of surveying, engineering drawings lofting and stitching, etc., so the results of the accuracy of coordinate transformation to meet the requirements. Therefore, the coordinate transformation model, coordinate conversion algorithm and Public Distribution issues Choosing and has its importance and necessity. The main content of this paper consists of three parts:First:the coordinates of the same benchmarks outlined under different forms and in different coordinate systems, summarize and analyze a variety of coordinate transformation model;Second:analysis and research as well as coordinate transformation algorithm different algorithm for coordinate conversion precision of coordinate transformation, specifically the traditional least-squares algorithm, the coordinates of the center of gravity algorithm, algorithm and total least squares algorithm based on the scale factor, search by example calculation accuracy better coordinate conversion efficient algorithms;Third:Analysis and Research Institute of the use of public-point conversion affect the accuracy of the coordinates, the number of points through public works case studies of local survey area, the common point of distribution and influence from the public point from several factors point to be converted to coordinate conversion accuracy explore public the number of points better conversion accuracy, the common point distribution and center of gravity position of the common point.