卫星天文导航自主定轨精度及误差分析

The accuracy and error analysis of satellite autonomous celestial navigation orbit determination

通过星敏感器和红外地敏观测星光角距是目前实现卫星天文自主导航最为工程可行的方法,但由于星上敏感器在测量过程中不可避免的会引入外部环境测量误差,导致观测量星光角距存在偏差,最终会造成卫星定轨结果不精确。为解决这一问题,结合实验数据分析,最终确定了敏感器存在的系统误差是造成卫星天文导航定轨精度较低的最大误差源,并利用最小二乘方法对敏感器系统误差进行标定,将标定之后的观测量通过卡尔曼滤波算法进行噪声消除,使观测量更加准确。最后,利用星上实际下传数据对此方法进行验证,取得了良好的效果。

Using the star sensor and infrared earth sensor to observe starlight angular is the most project way to implement the satellite autonomous celestial navigation. But because of the external environment measurement error during the process of star sensor measurement. It will lead to the starlight angle has errors and finally cause the satellite orbit results inaccurately. To solve this problem, and combined with experimental data analysis, we ultimately determine the sensor system error is the main source of error which to cause the satellite autonomous celestial navigation orbit determination has the less accuracy. And using the least squares method to demarcate the sensor system error. To make more accurate observations, we use Kalman filter algorithm to eliminate noise of demarcate observations. Finally, using the actual satellite downlink data to validate this method and achieved good results.