一种仅使用角度观测值的空间目标初始轨道确定方法

发布时间：2018-02-20 04:48

本文关键词： 空间碎片天基光学观测初始轨道确定距离搜索角度观测值　出处：《武汉大学》2017年硕士论文　论文类型：学位论文

【摘要】：空间目标广泛分布在不同的轨道上,其中绝大部分为空间碎片,严重威胁了在轨航天器的安全运行,需要对这些碎片进行有效地监测跟踪并进行碰撞预警。空间监测的主要技术手段包括光学、雷达和激光测距。地基光学监测手段受到了地理位置和观测时长的限制,仅仅依靠地基监测难以实现对大量空间目标的监测和编目库维护。天基空间监测技术和系统可以有效缓解上述两项限制:天基光学监测可以每天24小时进行;设计合理的天基监测星座可以实现全球覆盖。因此,天基空间监测也成为空间碎片探测的主要发展趋势。天、地基结合可使我国拥有独立自主、全球覆盖和准实时的空间预警能力,为确保国家空间战略基础设施的安全提供有力保障。利用天基光学监测技术建立和维护空间目标编目库涉及天基系统设计、观测值采集和处理、编目库设计等一系列问题。本文只对其中个别问题进行研究。本文首先分析了天基光学监测的可见性条件,并设计了一个包含6个轨道12颗卫星24个光学望远镜的SBSS星座,通过仿真该星座在不同观测时间段内的探测能力(可观测的空间目标数量),验证了天基光学观测手段的有效性。光学观测手段得到的观测值只包含角度信息,仅使用角度观测值的空间目标初轨确定是将新目标编目入库的关键之一。对于天基光学监测而言,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(这里称之为甚短观测弧段),使用传统的Gauss方法和Gooding方法很难确定空间目标的初始轨道。针对天基甚短弧段初轨问题,本文提出了一种基于距离搜索的新方法。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,筛选出一个最优的初始轨道结果。利用本文提出的方法对仿真的低轨空间碎片甚短弧段角度观测值进行初始轨道确定实验,将定轨结果与Gauss方法和Gooding方法所获得的结果进行比较,表明本文提出的方法在解的成功率和精度两方面都显著优于其他两种方法。对定轨误差进行分析,发现当观测值变化率较小时,初轨确定的精度明显下降,表明利用本文方法的初轨确定误差与角度观测值变化率之间有很大的关系。最后,将本文提出的方法扩展应用到天基高轨目标、地基空间目标角度观测值的初始轨道确定,实验表明,该方法都能得到较好的结果。仿真结果对今后开展空间目标天、地一体化监测系统的设计,监测作业规划、编目库建设等有一定的指导意义。
[Abstract]:Space objects are widely distributed in different orbits, most of them are space debris, which seriously threaten the safe operation of orbiting spacecraft. The main technical means of space monitoring include optics, radar and laser ranging. Ground-based optical monitoring means are limited by geographical location and duration of observation, It is difficult to realize the monitoring of a large number of space objects and the maintenance of cataloguing database by relying on ground-based monitoring alone. Space-based space monitoring technology and system can effectively alleviate the above two limitations: Space-based optical monitoring can be carried out 24 hours a day; A reasonably designed constellation of space-based monitoring can achieve global coverage. Therefore, space-based space monitoring has also become a major development trend in space debris detection. Global coverage and quasi-real-time space early warning capabilities to ensure the security of national space strategic infrastructure. The establishment and maintenance of a space-based object inventory using space-based optical monitoring technology involves the design of space-based systems, A series of problems, such as collection and processing of observations, design of cataloguing database, etc., are studied in this paper. Firstly, the visibility conditions of space-based optical monitoring are analyzed. A SBSS constellation consisting of 12 satellites in 6 orbits and 24 optical telescopes is designed. The effectiveness of space-based optical observation is verified by simulating the constellation's detection capability (number of observable space objects) in different observation periods. The observed values obtained from optical observation only contain angle information. The determination of the initial orbit of space objects using only angular observations is one of the keys to cataloguing new objects in the database. For space-based optical monitoring, low-orbit space-based optical telescopes are used to scan the low-orbit space debris. Because the relative motion of the two is faster, Angle observations can only be obtained in a very short period of time (here called very short observation arc). It is difficult to determine the initial orbit of space target by using the traditional Gauss method and Gooding method. In this paper, a new method based on distance search is proposed. The problem of pure angle initial orbit determination is transformed into an initial orbit determination problem based on two position vectors, and then the angle observations at other times are used for checking and constraining. An optimal initial orbit result is obtained, and the method proposed in this paper is used to determine the initial orbit of the simulated very short arc segment of Leo space debris. The results of orbit determination are compared with those obtained by the Gauss method and the Gooding method. The results show that the proposed method is superior to the other two methods in terms of the success rate and accuracy of the solution. The orbit determination error is analyzed. It is found that the accuracy of initial orbit determination decreases obviously when the rate of change of observation value is small, which indicates that there is a great relationship between the error of initial orbit determination and the rate of change of angle observation value by using the method in this paper. Finally, The method proposed in this paper is extended to determine the initial orbit of the space-based high orbit target and the angle observation value of the ground space target. The experimental results show that the method can obtain good results. The simulation results are useful for the future space target days. The design of integrated monitoring system, monitoring operation planning and cataloguing database construction have certain guiding significance.
【学位授予单位】：武汉大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：V412.41;V528

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