论文标题
使用Murchison广场阵列提高了对太空领域意识观察的敏感性
Improved Sensitivity for Space Domain Awareness Observations with the Murchison Widefield Array
论文作者
论文摘要
我们先前报道的使用Murchison广场阵列(MWA)对低地球轨道(LEO)环境进行了调查,该阵列(MWA)从被动雷达模式下的20个小时观察到了多个传球上70多个独特的居民空间对象(RSO)。在本文中,我们通过演示两种改善系统检测灵敏度的方法来扩展这项工作。第一种称为移位堆积的方法通过沿着天空中RSO轨迹的反射信号的空间相干集成的空间相干整合来提高微弱的RSO信号的统计学意义。该方法已在我们以前的盲目调查中使用的观察结果进行了测试,我们获得了75美元的检测总数$ 75 \%$。第二种方法将MWA重新定位到近场RSO的位置(观察后),通过对每个可见度进行复杂的相位校正以说明弯曲波 - 前弯曲。该方法在MWA的扩展阵列观察中成功测试了ISS通行证。但是,该方法目前受到长基线上的信号去溶性的限制(由于当前相关器的硬件约束)。我们讨论了MWA 3阶段相关器升级的RSO检测的灵敏度提高。我们通过简要评论将包含MWA技术的未来专用太空领域意识(SDA)系统来结束论文。
Our previously reported survey of the Low Earth Orbit (LEO) environment using the Murchison Widefield Array (MWA) detected over 70 unique Resident Space Objects (RSOs) over multiple passes, from 20 hours of observations in passive radar mode. In this paper, we extend this work by demonstrating two methods that improve the detection sensitivity of the system. The first method, called shift-stacking, increases the statistical significance of faint RSO signals through the spatially coherent integration of the reflected signal along the RSO's trajectory across the sky. This method was tested on the observations used during our previous blind survey, and we obtained a $75\%$ increase in the total number of detections. The second method re-focuses the MWA to the near-field RSO's position (post-observation), by applying a complex phase correction to each visibility to account for the curved wave-front. The method was tested successfully on an MWA extended array observation of an ISS pass. However, the method is currently limited by signal de-coherence on the long-baselines (due to the hardware constraints of the current correlator). We discuss the sensitivity improvement for RSO detections we expect from the MWA Phase 3 correlator upgrade. We conclude the paper by briefly commenting on future dedicated Space Domain Awareness (SDA) systems that will incorporate MWA technologies.