两种地球重力场模型在GNSS高程拟合中的适用性分析

Applicability Analysis of Two Earth Gravity Field Models in GNSS Elevation Fitting

为比较XGM2019e与EGM2008两种地球重力场模型在GNSS高程拟合中的适用性,基于“移去-恢复”法,使用平面拟合、二次曲面拟合及多面函数拟合在两个不同地形条件区域开展GNSS高程拟合实验。实验数据表明,在两个区域中,基于XGM2019e模型计算出3种不同拟合方法的外符合精度依次为2.22,1.62,1.85 cm及1.56,3.32,1.17 cm,均高于使用EGM2008模型计算出的外符合精度,表明在实验区域内使用XGM2019e模型进行GNSS高程拟合的效果优于EGM2008模型,将XGM2019e模型与不同GNSS高程拟合方法进行组合,还可进一步提升GNSS高程拟合精度。

In order to compare the applicability of two earth gravity field models named XGM2019e and EGM2008 in GNSS elevation fitting,a GNSS elevation fitting experiment was carried out in two regions with different terrain conditions using plane fitting,quadric surface fitting and polyhedral function fitting,based on the“remove-recovery”method.The experimental data shows that the external coincidence accuracy of three different fitting methods calculated based on XGM2019e model in the two regions are 2.22 cm,1.62 cm,1.85 cm and 1.56 cm,3.32 cm,1.17 cm which are higher than the external coincidence accuracy calculated by EGM2008 model.The results show that the effect of using XGM2019e model for GNSS elevation fitting in the experimental area is better than EGM2008 model,Combining XGM2019e model with different GNSS elevation fitting methods can further improve the accuracy of GNSS elevation fitting.