利用GOCE卫星观测数据反演地球重力场模型

利用GOCE卫星约6个月的重力梯度数据和约1 a的几何轨道数据，联合解算250阶次的地球重力场模型TJGOCE01。GOCE重力梯度数据的低频误差采用ⅡR数字滤波器处理，粗差采用阀值法和移动窗口阀值法组合探测与剔除。直接在梯度仪坐标系中建立GOCE卫星的重力梯度观测方程，采用改进的短弧边值法建立几何轨道观测方程。两类观测值的权根据其先验精度确定，采用Kaula规则约束的正则化方法解算法方程。解算的TJGOCE01模型相对于EIGEN6C2模型在250阶次的大地水准面误差和大地水准面累积误差分别为19.4 mm和177.9 mm。北美地区GPS水准观测数据的检验结果表明，TJGOCE01模型的中误差为0.544 m，略优于欧空局公布的同阶次的第二代时域法和空域法解算的GOCE重力场模型。

Gravity Field Model Recovery Using the GOCE Data

In this paper, a global gravity field model entitled TJGOCE01 up to the degree and order 250 is recovered from about 6 months of GOCE gravity gradient data and 12 months of GOCE orbit data, using a direct approach. The gravity gradient data are filtered by an infinite impulse bandpass digital filter, and gross errors are detected and removed using the threshold and a moving window threshold methods. The gravity gradient observational equations are established in the gradiometer coordinate system directly and the kinematic orbit observation equations are established by using a modified short-arc approach. The weights of the two kinds of observations are determined based on their prior accuracies, and the regularization approach based on Kaula’s rule is applied to solve the normal equation. The geoid error and cumulative geoid error up to degree and order 250 of TJGOCE01 model with respect to EIGEN6C2 model are 19.4 mm and 177.9 mm, respectively. The test results with the GPS leveling data in North America show that the root mean square error of TJGOCE01 model is 0.544 m, which is superior to the second generation models developed by the European Space Agency using time-wise and space-wise approaches.