基于精确星光大气折射观测模型的轨道摄动研究

基于星光折射间接敏感地平自主导航方法,改进了现有的大气密度模型和固定高度(25km)的观测模型,建立了自适应连续高度(20km～50km)的星光折射观测模型,并在此观测模型的基础上深入分析研究了影响导航精度的各种轨道摄动力,包括地球形状各阶摄动力、不同高度的大气阻力摄动力、太阳光辐射压力等.提出一种精简的大气模式--静止变标高球面大气,解决了由于高层大气密度的求解复杂,使大气阻力摄动模型不精确的问题,由此取得了较好的导航定位精度.利用UKF和EKF两种不同非线性算法,对考虑各种摄动力后的导航定位精度进行全面的计算机仿真实验,并就仿真结果进行了误差分析,同时研究了各种有关参数对导航精度的影响.

The Orbit Perturbation Research on the Stellar Horizon Atmospheric Refraction

Based on the stellar horizon atmospheric refraction concept for satellite autonomous navigation,the recently existing atmospheric model and the fixed altitude measurement model(25km) are modified,and then a self-adapted continuous altitude(20km-50km) measurement model is established.Using this measurement model,each orbit perturbation related to the navigation,including the higher order gravitational terms,air drag,solar pressure and so on is researched thoroughly.A condensed atmospheric model is brought forward to resolve the problem of the complexity of calculating the high altitude atmospheric density and the uncertainty of air drag perturbation model,which achieves an approving navigation precision.Finally,a simulation using both the unscented Kalman filter and the extended Kalman filter is carried out,also an error analysis is taken.At the same time,the effects of diversified correlative parameters on autonomous navigation are investigated.