不同插值法对下一代卫星重力反演精度的影响

Influences of Different Interpolation Methods on Accuracy of Next-Generation Satellite Gravity Recovery

开展了下一代GRACE Follow-On卫星重力反演的研究论证。第一,基于6点Lagrange和Taylor星间速度插值法,利用轨道参数(轨道高度250 km、星间距离50 km、轨道倾角89°、轨道离心率0.001)和关键载荷匹配精度(激光干涉测距系统的星间速度10-7m/s、GPS接收机的卫星位置10-3m和速度10-6m/s、加速度计的非保守力10-11m/s2),精确和快速反演了下一代GRACE Follow-On地球重力场;在120阶处,累计大地水准面精度分别为1.53×10-3m和2.51×10-3m。第二,基于6点Lagrange星间速度插值法反演下一代GRACE Follow-On地球重力场精度较基于6点Taylor星间速度插值法的反演精度平均提高2倍,因此Lagrange星间速度插值法对地球重力场反演精度的敏感性优于Taylor星间速度插值法。

The demonstration researches on the next-generation Earth＇s gravitational field recovery from GRACE Follow-On are carried out in this paper.Firstlly,based on the six-point Lagrange and Taylor intersatellite range-rate interpolation methods,using orbital parameters （orbital altitude of 250 km,intersatellite range of 50 km,orbital inclination of 89° and orbital eccentricity of 0.001） and the matching accuracies of key payloads （10^-7 m/s in intersatellite range-rate of the interferometric laser ranging system,10^-3 m in orbital position and 10^-6 m/s in orbital velocity of the GPS receiver,and 10^-11 m/s2 in non-conservative force of the accelerometer）,the next-generation Earth＇ s gravitational field from GRACE Follow-On is precisely and rapidly recovered; At degree 120,cumulative geoid height errors are 1.53 × 10^-3 m and 2.51 × 10^-3 m,respectively.Secondly,since the accuracy of the Earth＇ s gravitational field by the six-point Lagrange intersatellite range-rate interpolation method is about 2 times higher than that by the six-point Taylor intersatellite range-rate interpolation method,the sensitivity of the Lagrange intersatellite range-rate interpolation method to the accuracy of the Earth＇ s gravitational feild recovery surpasses that of the Taylor intersatellite range-rate interpolation method.