磁暴下的LEO卫星精密轨道确定

对低轨卫星（LEO）,大气阻尼摄动是主要的定轨误差源.尤其在发生磁暴时,求解一个大气阻尼因子的定轨方法已不能充分吸收大气密度计算不准所造成的定轨误差,因而在标校统一S波段（USB）的测量系统差和随机差时往往计算失真.本文提出了一种求解折线型Cd因子的新方法,克服了动力学模型不准所带来的定轨误差,通过与独立的GPS数据比较,定轨精度有明显提高,同时给出的测量系统差和随机差更加真实可信.

Precision Orbit Determination of Low-Earth Orbiters under Magnetic Storms

For low-earth orbiters(LEO),atmospheric drag is the main error source in orbit determination.During magnetic storms,solving one drag factor cannot completely absorb orbit determination errors due to imprecise atmospheric density computation.As a result,it usually distorts the estimation of measurement system error and random error when calibrating Unified S-Band(USB) tracking equipment.This paper proposes a new method through solving the fold-line C_d factors,which eliminates orbit determination error due to imprecise dynamical models.By comparing with independent GPS data,it can be seen that the accuracy of orbit determination is improved and the solved measurement system(error) and random error are more reliable.