考虑到不同坐标系所定义的几何意义与物理意义差异、大地网存在的局部变形和累积误差以及不同坐标系统坐标值的随机误差的影响,提出了一种基于方差分量的相似变换和多项式的坐标组合转换法,并应用于1980西安坐标系到2000国家大地坐标系的变换中,计算结果表明,组合转换法明显地提高了坐标转换的精度。
The different coordinate systems mean different geophysical concept. In the geodetic network the local deformation and accumulation error exist, and there are stochastic value in the common points with the differ- ent coordinate. So the coordinate transformation from low precise coordinate frame to the high one can not approve a high precise reference frame after this transformation. A combined method based on variance component estima- tion using similarity transformation and regressive approximating is presented. For the local error accumulation and distortion and the stochastic value of the common points, the accuracy of coordinate system is improved after the transformation with the combined method from Xi' an Geodetic Coordinate System 1980(XASS0) to China Geodetic Coordinate System 2000 (CGCS2000).