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。

Fast initial relative orbit determination method of angles-only relative navigation

For the problem of unobservable inter-satellite distance of angles-only relative navigation caused by the linear measurement model and relative motion model,a fast initial relative orbit determination(IROD)method of angles-only relative navigation is proposed.Firstly,the relative orbit elements(ROE)is used to establish a nonlinear relative motion model,which can decouple the inter-satellite distance and the relative orbital shape.Then,the inter-satellite distance near the collinear solution obtained by linear theory is changed,systematically,and a series of least-square fitting is performed,and then the dichotomy or Newton iteration method is used to find the optimal solution of the minimum fitting residual quickly in the global range.Finally,a semi-physical simulation platform is built to test the performances of the method in 4 orbital scenarios,and the effectiveness of the proposed method is verified.