如何利用诸如CHAMP、GRACE、GOCE等重力数据在重力场研究中占有重要的地位。从现有的方法看，基于线性化轨道扰动方程组的动力学方法起着基础的决定作用。项目将从另一个角度来导出该线性化轨道扰动方程组的等价形式，在此基础上引入非线性改正项；同时将对线性化轨道扰动方程组与新建立的顾及非线性改正的轨道扰动方程组分别进行精度估计，证明顾及非线性改正的轨道扰动方程组在恢复重力场时适用的时间弧长更长、精度更高；此外还将给出建立的轨道扰动方程组的具体解法，完整地建立起关于重力卫星的新的定轨理论和方法。另外，项目还将针对其它摄动力对卫星轨道的影响展开研究，其思路是导出这些摄动力作用于轨道的微分方程组，进而研究作用的结果与数学表示，以便将其它摄动力对观测数据的影响进行分离，达到提高处理实际卫星重力数据的精度。最后，将基于新理论和实际数据（例如GRACE数据）来恢复重力场的时变与静态模型。

It palys an important role in determining the gravity field how to exploit data of gravity satellites such as CHAMP, GRACE and GOCE. Among all methods to recover the gravity field from the satellite data, dynamical method based on linearized orbital perturbation equations plays a fundamental role. We will derive equivalent form of the above equations from other point of view and then introduce nonlinear corrections for them, so that orbital perturbation equations with nonlinear corrections can be established in project, and meanwhile the accuracy estimation and solving method for the established equations will be also given in project. In addition, the effects of other forces acting on satellite will be studied after deriving the corresponding differential equations. Finnaly, temporal and static models will be solved.