Research Of Transforming From Local Independent System To China Geodetic Coordinate System2000

Traditional geodetic survey has changed greatly with popularization of spacial survey technology and further improvement of precision. Geodetic coordinate system has transformed from reference ellipsoid centric coordinate system(RECCS)to geocentric coordinate system because of the change. The application of China Geodetic Coordinate System2000(CGCS2000)offers platform for establishment of China geodetic coordinate system with high precision, and eliminates the backward RECCS gradually. It is an important job to transform China geodetic coordinate system in using or Local Independent System(LIS)to CGCS2000 .This paper has studied on the relationships of transforming from LIS to CGCS2000 which can service to further scientific research and surveying works.This paper has inducted and analyzed some modes of establishing LIS according to sorts of LIS which set up in different historic periods by different industries and departments. There are three methods of LIS:First, selected ellipsoid of nation coordinate system, calculated plane rectangular coordinate by Gauss Krueger projection. Second, selected ellipsoid of Projection datum plane with compensation effect, calculated plane rectangular coordinate by Gauss Krueger projection. Third, added constant or translated and rotated the centre coordinate.This paper researched and presented the idea of transforming from LIS to CGCS2000 according to the use of geodetic survey and data. The dissertation selected rational coordinate transformation model, used coincidence points between two different coordinate system, calculated coordinate transformation parameter, evaluated coordinate transformation quality through assessment of coordinate transformation precision. Two kinds of methods have been used to transforming from LIS to CGCS2000: First, When both the methods of establishment are consistent, LIS2000 are transformed form LIS , and then CGCS2000 is transformed form the LIS2000. Second, opposite to above the central meridian is transformed by using the reference ellipsoid centric coordinate as transitional tool, then LIS2000 are transformed from LIS, CGCS2000 are reached at last.The author has computed some representative achievements and data of LIS ,and some good coordinate transformation methods are given . At last the coordinate transformation methods which are given by this paper are proved to be right through experiments.