重力场模型对低轨卫星定轨的影响

INFLUENCE OF GRAVITY FIELD MODELS ON ORBIT DETERMINATION OF LEOS

利用仿真观测数据,采用简化动力学低轨卫星定轨方法,分析了GEMT3、JGM3、EGM96、TEG4、EIGEN2和EIGEN-GL04C重力场模型对低轨卫星定轨精度的影响。结果表明,仿真得到的观测数据与实际情况比较符合,能够满足各种实验分析的需要;不同的重力场模型以及不同阶数对定轨精度有较大影响,采用由CHAMP或GRACE重力卫星数据得到的重力场模型定轨精度最高,与采用其他重力场模型相比,精度差异在cm级,最大达到22.47 cm,在定轨时应进行合理的选择。

Simulation of onboard GPS data was completed using the simulation model of Bernese software. With the observation data obtained from simulation,The influence of different gravity field models（ GEMT3、JGM3、EGM96、TEG4、EIGEN2 and EIGEN-GL04C） on the accuracy of orbit determination in low-orbit satellites was analized by simplified dynamic orbit determination method. The results show that the simulation data is consistent with actual situation,which can meet the need of a variety of experimental analysis. The influences of different gravity field models and degree on the accuracy of orbit determination are different,and the best result with the models generated from CHAMP＇s and GRACE＇s gravity data were achieved. Compared to the other gravitational field models,the accuracy difference of orbit determination with the method is in centimeter level.