格网内插法坐标转换

由于我国天文大地网存在较大的局部系统差和累积误差,采用Bursa模型完成坐标转换后往往还剩余较大的残差。为了提高转换精度,可以将转换区域划分为小的格网单元,利用数学模型计算得到每个格网节点的坐标转换改正量;再通过格网内插得到其中任意位置的坐标转换改正量,从而完成坐标转换。对同一区域分别用Bursa 7参数法与格网内插法进行了坐标转换,格网内插法的转换精度明显高于Bursa法。

The Method of Grid Interpolation Coordinate Transformation

In the astro-geodetic network of our country, large local systematic error and accumulative error exist, it is always the case that large residuals still remain after the transition to coordinate system adopting Bursa model. In order to improve transfor- mation accuracy, the transformation area is divided into small grid cells, then the coor- dinate transformation correction of each grid node is computed adopting mathematical model, finally, the coordinate correction of any place can be gotten by grid interpola- tion, and the coordinate transformation is achieved. In this paper, Bursa 7 parameters method and grid interpolation method were used for coordinate transformation on the same area, and the result is that the transformation precision of grid interpolation meth- od is significantly higher than Bursa 7 parameters method.