Angles-only initial relative orbit determination algorithm for noncooperative spacecraft proximity operations

This research furthers the development of a closed-form solution to the angles-only initial relative orbit determination problem for non-cooperative target close-in proximity operations when the camera offset from the vehicle center-of-mass allows for range observability.In previous work,the solution to this problem had been shown to be non-global optimal in the sense of least square and had only been discussed in the context of Clohessy–Wiltshire.In this paper,the emphasis is placed on developing a more compact and improved solution to the problem by using state augmentation least square method in the context of the Clohessy–Wiltshire and Tschauner–Hempel dynamics,derivation of corresponding error covariance,and performance analysis for typical rendezvous missions.A two-body Monte Carlo simulation system is used to evaluate the performance of the solution.The sensitivity of the solution accuracy to camera offset,observation period,and the number of observations are presented and discussed.

快速仅测角相对导航初始相对轨道确定方法

针对线性化的测量模型和相对运动模型会导致仅测角相对导航星间距离不可观测的问题,提出一种快速仅测角相对导航初始相对轨道确定(initial relative orbit determination,IROD)方法。首先,采用相对轨道根数(relative orbit elements,ROE)建立非线性相对运动模型,该模型可以将星间距离和相对轨道形状进行解耦。然后,在线性理论获得的共线性解附近系统地改变星间距离大小,并执行一系列最小二乘拟合,随后采用二分法或牛顿迭代法快速在全局范围内找到最小拟合残差的最优解。最后,通过搭建的半物理仿真平台对该方法在4种轨道场景中的性能进行仿真测试,验证了所提方法的有效性。