中文摘要：

利用改进的能量守恒法基于不同轨道高度恢复了120阶GRACE地球重力场。模拟结果表明：1）卫星轨道高度每降低100 km,大气阻力提高约10倍,不稳定的卫星平台工作环境将影响GRACE核心载荷的测量精度;2）地球重力场高频信号衰减较快,基于500 km轨道高度,在20阶处重力场衰减因子为0.221,衰减效应分别在50阶、80阶、100阶和120阶处增大了9.621倍、92.857倍、418.957倍和1 895.369倍;3）降低轨道高度有利于提高重力场恢复精度,采用美国JPL公布的GRACE其他指标,在120阶处基于500 km轨道高度恢复累计大地水准面精度为17.316 cm,分别基于450 km、400 km和350 km轨道高度恢复精度提高了1.566倍、4.502倍和10.871倍;4）如果卫-卫跟踪测量模式中轨道高度设计为350～400 km有利于120阶地球重力场的恢复。

英文摘要：

The GRACE Earth＇ s gravitational field complete up to degree and order 120 is recovered based on different orbital altitude according to the improved energy conservation principle. The simulative results show： Firstly, with the decrease of orbital altitude per 100 km, atmospheric drag will increase 10 times approximately, and the unstable work environment of satellite platform will influence the measuring accuracy of GRACE key pay- loads. Secondly, the high-frequency signals of Earth＇ s gravitational field will be attenuated quickly. Attenuation factor comes to 0. 221 based on 500 km orbital altitude at degree 20, and attenuation effects increase 9. 621 times, 92. 857 times, 418. 957 times and 1895. 369 times at degree 50^th, degree 80^th, degree 100^th and degree 120^th, respectively. Thirdly, low orbital altitude is good for improving the accuracy of Earth＇ s gravitational field recovery.Cumulative geoid height error is at the level of 17. 316 cm using 500 km orbital altitude at degree 120^th, and the accuracies improve 1. 566 times, d. 502 times and 10.871 times as using 450 km, 400 km and 350 km orbital ahitude combined with GRACE other indexes published by JPL, U. S. , respectively; Lastly, orbital altitude designed as 350 - 400 km for future satellite-to-satellite tracking model will be propitious to the Earth＇ s gravitational field recovery complete up to degree and order 120.