重力卫星串联编队仿真分析

现有重力卫星任务存在时空分辨率不足、时空混频以及重力场信号各向异性等局限性.分别对重力卫星串联编队的轨道高度、轨道倾角、星间距离等指标进行仿真分析,就重力卫星串联编队星座模式对重力场时空分辨率的影响进行了数值分析.结果表明,卫星轨道高度的选择需要兼顾重力场信号衰减和卫星寿命等因素,以维持在300～400 km为优;轨道倾角选择应充分考虑极空白问题的影响,极空白区大小不宜超过6°;星间距离大于250 km时,重力场精度的提升并不明显,重力卫星串联编队星间距离设为50～100 km为优.重力卫星串联编队星座模式可同时有效提升地球重力场时空分辨率,实现时变重力场的各向同性探测.

Simulation Analysis of GRACE type Gravity Satellite Formation

The gravity satellite missions launched have the limitations in insufficient spatial and temporal resolution, space time aliasing, and anisotropy of the gravitational field signals. The orbit altitude, the orbit inclination and the inter satellite range of GRACE type gravity satellite formation were simulated and analyzed. The numerical analysis of the impact of two GRACE type gravity satellite constellation on the spatial and temporal resolution of gravity field was carried out. The results show that, considering the signal attenuation of gravity field and the life of the satellite, the satellite formation orbit altitude is better at 300~400 km. The choice of the orbit inclination should consider the influence of the polar gaps sufficiently, and the gap size should not exceed 6°. Also, when the inter satellite range is greater than 250 km, the improvement of the gravity field accuracy is not obvious, and the inter satellite range is excellently set to 50~100 km. Besides, the constellation including two GRACE type gravity satellite formation can effectively enhance the spatial and temporal resolution of the earth''s gravity field at the same time to achieve isotropic exploring of the time variable gravity field.