低低重力卫星KBR和ACC噪声敏感度分析

Sensitivity analysis of KBR and ACC load noise for SST-LL gravity satellite

利用低低卫卫跟踪观测数据所解算的时变重力场是探测分析全球质量变化迁移的重要手段。利用一个月的低低跟踪模式卫星仿真观测数据,分析了星间距离变率误差和加速度计误差对重力场模型解算精度的影响。结果表明:以3×10^(-10)m/s^(2)的加速度计观测误差和5×10^(-7)m/s的距离变率观测误差为基准,当加速度计误差增大一个量级时,截断至120阶次重力异常累积阶误差为3.39mGal;当星间距离变率误差增大一个量级时,截断至120阶次的重力异常累积阶误差为12.39mGal,远大于参考设计指标2mGal。通过比较分析可以说明,星间距离变率误差比加速度计误差对重力场模型精度影响更为敏感,这对低低跟踪体制重力卫星设计、重力卫星下传数据预处理有重要参考意义。

The time-varying gravity field calculated from low and low satellite tracking observation data is an important means to detect and analyze global mass change and migration.In this paper,the influence of inter satellite distance variability error and accelerometer error on the precision of gravity field model is analyzed by using one month low tracking mode satellite simulation observation data.The results show that:based on the accelerometer observation error of 3×10-10 m/s?and the distance variation observation error of 5x 10-7 m/s,when the accelerometer error increases by an order of magnitude,the cumulative order error of gravity anomaly truncated to 120 orders is 3.39 mGal;when the inter satellite distance variability error increases by an order of magnitude,the cumulative order error of gravity anomaly truncated to 120 orders is 12.39 mGal,which is far greater than the reference design index of 2 mGal.The analysis show that the inter satellite distance variation error is more sensitive to the precision of gravity field model than the accelerometer error.This has important reference significance for the design of SST-LL gravity satellite and the data preprocessing.