小尺寸空间碎片的轨道编目方法研究

Organizations such as NASA and ESA are dedicated in research on cataloguing space debris with size smaller than 10cm, and are focusing on developing observation facilities of next generation. But it is also necessary to improve the cataloguing method such that the difficulties raised by sharply increasing number of space debris can be resolved. In our proposal, we are intent to find the approach to the problems of new debris recognition and updating orbit of catalogued debris which are the two key issues in cataloguing when space density of debris becomes very high. To be specific, to recognize new space debris, we will divide the uncorrelated observation into groups with feature information contained in observation data, such that the similarity of uncorrelated observations in a single group can be reduced, and the rate of recognizing observations come from same space debris can be improved. To update the orbit of catalogued small debris, we will establish a model to calculate the update period considering the evolution of orbit errors and the distribution of small debris orbits, and an algorithm of discriminating wrong correlation results will also be formed. In order to test our methods, a simulation model will be established in which the influence of errors come from observations and orbit model will be analyzed. The results of our proposal will be the basis of the realization of small debris cataloging.

目前国际上主要的航天机构都将10厘米以下小碎片的轨道编目作为未来目标，并投入大量精力进行新一代监测设备的研发。但要对数十万个小碎片进行编目，还需要建立一套新的轨道编目方法以解决由编目碎片数量的激增所带来的问题。在本项目研究中我们主要针对空间碎片轨道编目中面临的两个关键问题：新碎片的识别编目和已编目碎片的轨道更新，建立一套小碎片轨道编目的方法。具体而言，针对新碎片的识别编目问题我们将利用特征测量信息对未关联观测数据进行分组处理，以降低数据间的相似度，提高同源数据的识别率；针对已编目碎片的轨道更新问题我们将依据小碎片的分布和轨道误差演化规律建立轨道更新周期的计算模型，并建立利用后续数据甄别错误关联的方法。此外我们还将建立小碎片轨道编目的仿真模型以验证编目方法的可行性，并对观测误差、轨道模型误差等主要误差源的影响进行深入分析。本项目的研究成果将为实现小碎片的轨道编目提供理论基础。

尺寸大于1厘米的空间碎片均会对在轨卫星造成致命的撞击伤害。空间碎片的轨道编目是实现碰撞预警和规避的前提条件。随着国际社会的空间碎片威胁愈加关注，探测技术、监测网优化调度技术、数据处理技术的不断进步，编目更小尺寸空间碎片正在成为空间碎片领域的一个重要发展趋势。要实现小尺寸空间碎片的轨道编目除了要大幅提升探测设备的极限探测能力，还需要在设备的优化调度、小尺寸碎片的关联等方面开展研究，以解决小尺寸空间碎片数量大、轨道精度低等问题。本项目通过粒子群算法，初步实现了空间碎片探测设备的组网优化调度，可在探测设备能力一定的情况下探测更多的空间碎片；在关联问题的研究方面，通过对多假设跟踪问题和新碎片跟踪策略问题的研究可以提高对新发现小碎片的编目效率，并且量化分析了小尺寸空间碎片的轨道预报模型精度和平均位置差，给出了实现小尺寸空间碎片编目的探测频次分析方法。