研究了简化动力学定轨方法中伪随机脉冲的定义、特征及估计的数学模型。结合CHAMP星栽GPS实测数据,讨论了不同力学模型及观测值情况下的随机脉冲的估计,并分析了随机脉冲在不同情形下的大小变化及其对定轨精度的调节作用。结果表明,随机脉冲的大小和使用的力学模型、是否估计经验参数及使用的观测值精度有关系。在力学模型误差较大的情况下,随机脉冲的设置能有效地补偿和吸收模型误差,从而提高定轨精度。
The definition, characteristics and mathematical model of pseudo-stochastic pulses utilized in reduced-dynamic orbit determination are systematically analyzed. With the help of the real onboard GPS observations from spaceborne receiver on CHAMP satellite, the stochastic pulses are estimated with different force models and observations of different types, and the variation of stochastic pulses in different cases and adjust impact of pulses on orbit accuracy are analyzed in detail. The results show that the sizes of stochastic pulses mainly depends on the force models, whether estimating experience parameters or not and accuracy of observations used. In the cases of relatively big model errors, the set of stochastic pulses can efficiently compensate or absorb the impacts of model errors, so the orbit accuracy can be improved accordingly.