基于Unscented卡尔曼滤波器的卫星自主天文导航研究

针对星光折射间接敏感地平的卫星自主天文导航方法，建立了带摄动项的状态方程和以星光视高度为观测量的量测方程。由于该状态方程和量测方程都是严重非线性的，利用推广的卡尔曼滤波器进行导航时精度较低。Unscented卡尔曼滤波是一种针对非线性系统的估计新方法。本文提出将Unscented卡尔曼滤波用于自主天文导航。计算机仿真结果显示Unscented卡尔曼滤波的估计精度远优于推广的卡尔曼滤波。

Study of the satellite autonomous celestial navigation based on the unscented kalman filter

The method of the satellite autonomous celestial navigation by indirectly sensing horizon through stellar atmospheric refraction was studied.The state equations with the perturbation items and measurement equation with the ray apparent height as the observation were established.Because the state equations and measure equation are highly nonlinear,the precision of the Extended Kalman filter is poor when the filter is applied to this navigation estimation.The Unscented Kalman filtering is a new estimation method aimed at nonlinear system.It was applied to the autonomous celestial navigation,and the computer simulation was performed.The results demonstrate that the precision of the Unscented Kalman filtering is much higher than the Extended Kalman filtering.