In this paper we consider the use of wide field of view radar sensors such as the Murchison Widefield Array (MWA), a low frequency radio telescope designed for astrophysics and cosmology, for rapid response observations of the debris clouds produced by collisions between objects in Earth orbit. With an increasing density of objects in Low Earth Orbit, including legacy assets used by the astronomy community over decades, the risk of new debris clouds forming is also increasing. The MWA constitutes a wide field, rapid response passive radar system and we explore its likely performance in the detection and characterisation of debris clouds. In general, astronomy facilities such as the MWA can play a role in protecting the space environment for the future. In order to undertake this work, we adapt the NASA EVOLVE 4.0 breakup model, utilising the EVOLVE outputs to produce representative dynamic debris clouds. We find that the MWA is likely to detect a large fraction (>70%) of modelled debris cloud fragments for collision masses between 100 kg and 1000 kg for orbits in the lower part of LEO, if the MWA can achieve close to optimal detection sensitivity. Useful detection fractions are still achieved for more conservative assumptions. The detection fraction of fragments decreases as a function of altitude and inversely with collision mass. Encouragingly, we find that the wide field nature of the MWA allows the full evolving debris clouds to be observed in a single observation, with only $\sim2\%$ of the debris fragments escaping the sensitive portion of the field of view after 100 seconds, for all collision masses and altitudes. These results show that the MWA is an intrinsically useful facility for the rapid characterisation of debris clouds, but that work is required to achieve the data processing within an appropriate timeframe to provide rapid alerts.

中文翻译：

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使用默奇森宽场阵列射电望远镜模拟由破裂事件引起的轨道碎片云及其表征

在本文中，我们考虑使用宽视场雷达传感器，例如默奇森宽场阵列 (MWA)，这是一种为天体物理学和宇宙学设计的低频射电望远镜，用于对地球物体之间碰撞产生的碎片云进行快速响应观测轨道。随着近地轨道物体密度的增加，包括天文学界几十年来使用的遗留资产，新碎片云形成的风险也在增加。MWA 构成了一个广域、快速响应的无源雷达系统，我们探索了它在探测和表征碎片云方面的可能性能。总的来说，MWA等天文设施可以在保护未来的空间环境方面发挥作用。为了承接这项工作，我们改编了 NASA EVOLVE 4.0 解散模型，利用 EVOLVE 输出生成具有代表性的动态碎片云。我们发现，如果 MWA 能够实现接近最佳检测灵敏度，则 MWA 可能会检测到大部分 (>70%) 的模拟碎片云碎片，用于 LEO 下部轨道的碰撞质量在 100 kg 至 1000 kg 之间. 对于更保守的假设，仍然可以获得有用的检测分数。碎片的检测分数随着高度的变化而降低，与碰撞质量成反比。令人鼓舞的是，我们发现 MWA 的宽视场性质允许在一次观测中观察到完整的演化碎片云，100 秒后只有 $\sim2\%$ 的碎片碎片逃离视场的敏感部分，对于所有碰撞质量和高度。