Determination Of Accuracy And Accuracy Of Reference Ellipsoidal Parameters In Locally Coordinate System

With the approval of the State Council, China Geodetic Coordinate System2000(CGCS2000)has been put into service since July1st,2008. According to the authorization, national SMC has issued the implementation scheme of national coordinate system2000(countries word[2008]24), and required that the transition and conversion between the current national geodetic coordinate system and CGCS2000should be achieved within8years or10. At present, most of scale map data and geographic information systems adopt1980Xian coordinate system; except GPS measurement, which adopts WGS84world coordinate system, the others adopt1954Beijing coordinate system or independent coordinate system. Therefore, in the transition period, the above coordinate systems will be used simultaneously. realizing the smooth transition of coordinate systems and meeting the need of surveying and mapping work ale two urgent tasks that the workers of surveying and mapping must accomplish.Most cities and regions due to the urban construction and the needs of the engineering survey and the local coordinate system is established, and the local coordinate system the ellipsoid is used in countries on the basis of the reference ellipsoid to change and, and we call it "regional ellipsoid. In this paper, the local coordinate system to national coordinate system to solve the relationship between the parameters of the local reference ellipsoid coordinate system.Based on the coordinate system1987kunming and CGCS2000under public control points for the1987kunming coordinate system reference ellipsoid parameters and accuracy analysis. Content mainly includes the following several aspects:(1) Introduced the earth ellipsoid and the establishment of the geodetic coordinate system, the coordinate system of the currently used in China has made the simple introduction.(2) Arc measurement are introduced for reference ellipsoid parameter method for ellipsoid in geodesy and the use of the formula. (3) Combined with1987kunming coordinates and CGCS2000under public control points, using arc measurement the geodetic coordinate differential equation and least square method to solve the reference ellipsoid parameters and analyze the precision of the parameter study.