两种推估模型在格网坐标转换中的应用

APPLICATION OF TWO PREDICTION MODELS IN GRID COORDINATE TRANSFORMATION

2000国家大地坐标系(CGCS2000)的启用,使得许多测绘成果的坐标面临转换,需要研究具有较高精度的坐标转换方法。天文大地网向高精度地心坐标系进行坐标转换时,使用Bursa模型在完成转换后仍留有较大的残差,为了提高转换精度,使用格网坐标转换方法对残差进一步拟合,并将协方差函数推估模型和多面函数推估模型分别用于推估格网节点的坐标残差改正量。实验分析表明,基于这两种推估模型的格网坐标转换方法转换精度相当,均可有效地拟合剩余残差,使得整体转换后的残差保持在一个较小的量级,取得较高转换精度。

As China Geodetic Coordinate System 2000 （CGCS2000） starts being used, the coordinate of surveying and mapping products need to be transformed and the method of coordinate transformation with high accuracy also need to be studied. Large residuals still remain after the transition by use of Bursa model from the astro-geodetic network of our country to high-precision geocentric coordinate system. In order to improve transformation accuracy, grid coordinate transformation is used to fit residuals further, in which covariance function and muhi-quadric function prediction model are respectively adopted to predict the coordinate correction of grid node. The experiment shows that the accuracies of these grid coordinate transformations on the two above prediction models are similar, so the two models are able to fit remaining residuals effectively. The residuals which remain after the whole transformation are in a low level and the high transformation accuracy is achieved.