使用低轨天基光学望远镜扫描式观测低轨空间碎片,由于两者的相对运动较快,只能获得很短时间内的角度观测值(甚短观测弧段),使用传统的Gauss方法和Gooding方法很难得到精确的空间碎片初始轨道.为此,文章提出了一种新的方法,在给定的一组角度观测值中,通过搜索其中2个时刻的距离信息,将纯角度的初始轨道确定问题转换为基于2个位置矢量的初始轨道确定问题;再利用其他时刻的角度观测值进行检核和约束,筛选出最优的初始轨道结果.利用文章方法对空间碎片在10～60 s内的503个观测弧段进行处理,结果表明,其定轨误差与角度观测值变化率有关.将文章方法所得结果与Gauss方法和Gooding方法进行比较,证明文章方法在解的成功率和精度上都显著优于其他2种方法,能很好地确定空间碎片的初始轨道.%When a LEO space debris is optically observed in the scanning mode from a LEO space based telescope,only angular observations in a very short time (very short observation arc)can be collected due to high relative velocity between the debris and the telescope.It is usually difficult to obtain accurate IOD (initial orbit determination) results from such short-arc angles by using traditional Gauss and Gooding methods.In this paper,a new method is proposed to tackle this very short-arc angles-only IOD problem.In a set of given angular observations,the ranges at two epochs are tested through a step-by-step search procedure and making the problem of angles-only IOD transforming to the problem of two position vector IOD.Then,the angular observations of other epochs are used in judgment foundation of the IOD solutions to obtain an optimal solution.The method is applied to process 503 observation arcs of space debris between 10 and 60 seconds,and the results show that the errors of IOD are principally influenced by the variation rate of angular observations.Comparisons with the resuits using the Gauss and Gooding methods show that,the proposed method is significantly superior over the other two methods in both the solution success rates and accuracy,which can be used to determinate the initial orbit of space debris.
展开▼
