The Method of Inter-Transformation between Horizontal and Space Coordinate

摘要

Realizing coordinates transformation between WGS-84 datum and local datum is the key problems of GPS surveying. It is difficult to obtain the precise geodetic height in the national or local coordinate system which affects the accuracy of 7 parameter models. This paper puts forward a way of transformation which can achieve the WGS-84 to BJ-54 and WGS-84 to Xi'an 80 coordinate transformation combining with an "adjustment" method. It only needs to know the horizontal coordinate of each datum. The results of experiment show that in a certain longitude-latitude grid it is able to achieve the high accuracy horizontal coordinate transformation to meet the demand of the actual work in the case of lacking geodetic height.