中文摘要：

基于改进的能量守恒法,分别利用先验地球重力场模型法（PEM）和最小二乘协方差阵法（LSM）评定了120阶GRACE地球重力场的精度,模拟结果表明：1）基于美国JPL公布的GRACE轨道参数和核心载荷精度指标,在120阶处分别采用PEM和LSM恢复地球引力位系数的精度为5.192×10^-10和6.633×10^-10;2）分别基于PEM和LSM恢复120阶地球引力位系数的模拟精度和德国GFZ公布的EIGEN-GRACE02S地球重力场模型的实测精度在各阶处符合较好,从而证明了基于PEM和LSM评定地球重力场恢复精度的有效性;3）通过基于PEM和LSM分别恢复地球引力位系数的模拟精度在各阶处的符合性,验证了基于能量守恒法结合预处理共轭梯度迭代法恢复120阶GRACE地球重力场算法的可靠性。

英文摘要：

The accuracies of GRACE Earth＇ s gravitational field complete up to degree and order 120 are evaluated by using the prior Earth＇ s gravitational field model method （ PEM ） and least - squares covariance method （LSM） on the basis of improved energy conservation principle, respectively. The simulative results are as follows. Firstly, based on the GRACE orbital parameters and accuracy indexes of key payload instruments, the accuracies of geopotential coefficients are 5. 192 × 10^-10 and 6. 633 × 10^- 10 by using the PEM and LSM at degree 120. Secondly, simulative geopotential coefficients degree RMS errors obtained by using the PEM and LSM accord with the measured accuracy of Earth＇s gravitational field model EIGEN -GRACE02S provided by German GFZ ,and the validity of evaluating the accuracy of Earth＇ s gravitational field based on the PEM and LSM is proved. Thirdly, on the basis of coincidence of simulative geopotential coefficients degree RMS errors obtained by using the PEM and LSM, the algorithm dependability of the GRACE Earth＇ s gravitational field recovery complete up to degree and order 120 based on the energy conservation principle associated with the pre -conditioned conjugate -gradient iterative approach is validated adequately.