航天器天文导航中星敏感器最佳安装方位研究

航天器自主天文导航中,通常用星敏感器和地平仪测量的星光角距作为观测量,星敏感器安装方位角是影响导航精度的一个重要因素.针对星光角距作为观测量的自主天文导航方法,分别采用扩展卡尔曼滤波EKF(Extended Kalman Filter)和Unscented卡尔曼滤波UKF(Unscented Kalman Filter)2种滤波方法进行仿真计算,研究了星敏感器安装方位角对导航精度的影响规律,得出星敏感器的最佳安装方位角,并考察了其在不同轨道参数下的适用性,为星敏感器的安装和星敏感器视场内观测星的选取提供了依据.仿真计算表明,本结论对其它利用"星光+地平"的自主导航方法也适用. 

Optimum installation azimuth of star sensor for spacecraft celestial navigation

Starlight angular distance detected by star sensor and horizontal instrument as the observation is often used for spacecraft autonomous celestial navigation.Installation azimuth of star sensor has a significant effect to navigation precision.An investigation on autonomous celestial navigation using the starlight angular distance as the observation was presented.The effects of the installation azimuth of star sensor to the error determination were simulated using EKF(extended Kalman filter)and UKF(unscented Kalman filter)respectively.Some rules about how the installation azimuth of star sensor affects the navigation precision were summarized and some theory analyses were given.The optimum azimuth of star sensor was given and its applicability under different orbit parameters was analyzed.The simulation result indicates the optimum azimuth can be used to guide star sensor installation and star selection in the field of view.All these results also apply to the other autonomous navigation systems that use the information of starlight and horizon as their observation.