Local Area Wgs-84, Beijing 54 And 80 Xi'an Coordinate Conversion Applied Research

In recent years,. the Geographic Information System applied to land resource field quickly and widely, whether the second national land survey, the mining right to be checked on the spot, or a nationwide are now for land development and consolidation and the middle-and-low-yielding fields reconstruction planning, mineral resources utilization situation investigation, a wide range of national projects, are closely related with geographic information system, and in the Geographic Information System except computer science another key point is spatial-temporal distribution.As the effective method to describe space position, coordinates is almost involves all of the geographic information related projects. GPS technology as a very effective method for space location information in recent years have been very good development.GPS system are usually geodetic coordinates in WGS-84 coordinate system, and the geodetic coordinates in practical engineering application are generally used in 1980 xi'an coordinates,1954 Beijing coordinate or local independent coordinate system. Coordinate transformation is used in the production practice of processing methods, there has been relatively mature transformation methods and theories, but the existing conversion method is often imprecised, especially from a 1954 Beijing coordinate to 1980 xi'an coordinate conversion are not a tight conversion process, not a general parameter, which this leads to different production units of various projects and different operation technical personnel to the reliability of coordinate transformation results may not agree, in some cases will cause unnecessary consumption.Firstly in this paper introduces some key technologies and basic theories, including the geographic information system, GPS technology overview, the ellipsoid description, coordinate and ellipsoid coordinate description, the basic theory of coordinate transformation and the research status of coordinate transformation. Secondly introduced the conversion process between WGS84 coordinate,1980 xi'an coordinate and 1954 Beijing coordinate. The key part on this paper is discussed the public point distribution of coordinate transformation of precision based on experimental data. In all cases verification of public point distribution of coordinate transformation precision degree of influence, for specific engineering application for reference.Specific experimental method can be described as the general public point by changing the options and public point for change of some public points'accuracy class, each of the transformation parameters under the scheme, reuse of statistical methods for conversion analysis results, some conclusions are given for the specific engineering application, provide the beneficial reference.