Walker星座自主定轨误差分析

通过对Walker星座中卫星间的相对运动进行分析,给出星间相对距离的解析表达式及其对轨道根数的偏导数,直观地描述在同轨道面和异轨道面的星间观测对轨道根数变化的体现情况;根据星座中卫星的相对位置,提出合理的约束条件和平差方法,利用星间测距网实现星座的整网定位;通过仿真算例,比较在不同情况下,采用合适的整网定位方法对轨道根数的系统误差和随机误差修正的情况。

Error Analysis of Autonomous Orbit Determination for Walker Constellation

Since there are more and more satellites in the constellation, autonomous position determination by using single satellite has been gradually replaced by the whole autonomous navigation by using the inter-satellite relative observation in the constellation. Based on analyzing inter-satellite relative movement for Walker constellation, the resolution expression of the inter-satellite relative distance and the partial derivative with respect to orbit elements are presented firstly. The variation of orbit elements in the inter-satellite measurement is intuitively described in the same orbit plane and different orbit plane. Secondly, based on the relative position of satellites in the constellation, rational restriction and estimation method is put forward. The orbit determination of the whole network of the constellation is realized using the measurement of the inter-satellite distance. Finally, modified results of the orbit elements' system error and random error are compared in different instance using the rational orbit determination method by way of example.