地球重力场恢复中的位旋转效应

分析了地球自转引起的位旋转效应公式中采用近似速度的影响. 对一组GFZ的快速科学轨道、一组TUM的约化动力法轨道以及一组GFZ的事后科学轨道，计算了星历提供的速度与只有地球引力场对卫星产生作用时的卫星速度的差值，其中参考重力场模型分别采用EGM96、EIGEN2和EIGEN_CG01C. 通过比较得出：轨道数据与EIGEN2地球重力场模型的自恰性优于EGM96和EIGEN_CG01C地球重力场模型. 速度差各分量的变化具有很明显的周期性且与卫星轨道的运行周期相吻合. 当要求在卫星轨迹处获得1m2/s2精度的扰动位时，也即要求位旋转效应公式中卫星速度的近似精度小于2mm/s时，GFZ的快速科学轨道、TUM的约化动力法轨道只需要剔除那些速度精度不满足要求的卫星轨迹点；当要求在卫星轨迹处获得05m2/s2精度的扰动位时，应当重新估算上述轨道的速度信息，或采用精度更高的GFZ事后科学轨道.

The rotation of the gravity potential on the Earth's gravity field recovery

We analyze the effect of approximate velocity in the formula of the rotation of the gravity potential, which is caused by the Earth rotation. We compute the difference between the satellite ephemeris's velocity and numerical integral's velocity. The ephemeris data come from GFZ's Rapid Science Orbit, TUM's Reduced-Dynamic Orbit, and GFZ's Post-processed Science Orbit respectively. The integral data are obtained based on the reference gravity field models EGM96, EIGEN2, and EIGEN-CG01C, respectively. The fitting between ephemeris velocity and integral velocity depended on EIGEN2 reference gravity field model is better than the EGM96 and EIGEN-CG01C model. The variations of velocity difference have obvious periodicity, which coincides with the satellite orbit period. When the disturbing potential of 1m~2/s~2 accuracy, or the approximate velocity of accuracy less 2mm/s in the formula of the rotation of the gravity potential is required, the satellite orbit data not satisfied the potential rotation computing demand are rejected from the GFZ's Rapid Science Orbit and TUM's Reduced-Dynamic Orbit. If the disturbing potential is desired 0.5m~2/s~2 at satellite track, the satellite velocity required in formula of the rotation of the gravity potential should be re-computed or the GFZ's Post-processed Science Orbit is adopted.