地球重力场模型在高程控制网中的应用

Application of Gravity Field Model in the Height Control Network

不同地球重力场模型的优选及不同拟合方法的合理选择是GPS高程转换所需考虑的关键问题。随着以卫星重力梯度为主要观测值的GOCE重力卫星的发射成功及其相关重力场模型的推出,地球重力场模型的精度及分辨率有了较大提高,有必要将其应用于GPS高程转换的研究。本文提出了用目前具有较高精度的SGG地球重力场模型来代替以往较低精度地球重力场模型的策略,计算分析了这种模型解算全球高程异常的精度,并将这种模型应用于"移去—拟合—恢复"法的GPS高程转换中,使GPS提供真正意义上的三维坐标。

The key problem of transferring GPS leveling is to get an optimal combination of different gravity models and a reasonable selection of different fitting methods. With the successful launching of GOCE gravity satellite which takes gravity gradient as main observations, and its relevant production of gravity model which greatly improves the accuracy and resolution of the Earth gravity field model, it is necessary to apply it to GPS lev- eling transformation. This article proposes a method of using the latest higher precise SGG gravity model to re- place the gravity model in the past, and analyzes the precision of height anomaly calculated respectively by the models. We apply the models to the method of ＂recovery- fitting- restore＂ of GPS height transformation and make the GPS provide real sense of the three-dimensional coordinates.