仅有相对视线角测量时的椭圆轨道交会相对导航分析

对仅有相对视线角测量时的椭圆轨道交会相对导航问题进行了分析．借鉴已有研究成果，给出仅有相对视线角测量时，相对导航系统可观的定义，以及为使系统可观，加速度项所需满足的充分必要条件；分析指出由于相对动力学模型误差的存在，相对导航系统始终是可观的，但可观度很弱；而追踪器进行适当的机动可极大改善系统的可观性，给出为使系统可观，机动加速度具体所需满足的充分必要条件；指出当通过施加机动加速度改善系统的可观性时，获取零输入相对位置矢量方向是前提条件，并论证了利用相对视线角测量信息，可以对零输入相对位置矢量方向进行估计和预测．

Angles-Only Relative Navigation for Elliptical Orbit Rendezvous

The problem of angles-only relative navigation for elliptical orbit rendezvous is analyzed in this paper. On the basis of other scholars＇ achievements, the definition of the observability of relative naviga- tion system with angles-only measurements is given, and the necessary and sufficient condition the input should satisfy to make the system observable is proposed, the paper points that the system is always observable because of the existence of dynamic model error, but the degree of observability is very week ; in addition,appropriate maneuvering acceleration can improve the degree of observability, and the concrete necessary and sufficient condition the maneuvering acceleration should satisfy is deduced in the paper. At last, geometrical explanation of the system observability with maneuvering acceleration shows that it is essential to know the direction of the relative position vector without regard to maneuvering acceleration, and it can be proved that the direction of the relative position vector with zero input can be estimated and predicted using measurements for relative angles.