利用火球网络追踪更频繁的再入事件：基于视频记录的猎鹰9号上面级轨道确定
Using fireball networks to track more frequent reentries: Falcon 9 upper stage orbit determination from video recordings
AI总结：
本研究利用西班牙流星网络视频记录，通过调整平面相交方法确定猎鹰9号上面级再入轨道，并估计脱轨危险区，强调地面网络在监测人造物体再入中的作用。
摘要：
2021年2月16日，西班牙流星网络（SPMN）记录到一个在 Mediterranean 上空缓慢移动的人造物体。根据天体测量数据，我们确定该事件为 SpaceX 猎鹰9号运载火箭上面级的再入发动机点火。为详细研究这一事件，我们调整了平面相交方法，该方法原本用于近直线流星体轨迹，现用于分析与人造物体相关的缓慢且弯曲的轨道。为验证我们的结果，我们利用美国政府联合太空作战中心（CSpOC）编目的四块“碎片”近似了上面级的轨道要素。基于这些计算，我们还利用 MSISE90 模型大气估计了可能的脱轨危险区。我们警告这些人造火流星可能对火球研究造成的干扰。此外，鉴于未来人造火流星可能更加频繁，我们指出地面探测网络在监测近地空间中潜在危险人造物体以及确定人造空间碎片散布场方面可以发挥的新作用。
英文摘要：
On February 16, 2021, an artificial object was recorded by the Spanish Meteor Network (SPMN) moving slowly over the Mediterranean. From the astrometric measurements, we identify this event as the reentry engine burn of a SpaceX Falcon 9 launch vehicle's upper stage. To study this event in detail, we adapted the plane intersection method for near-straight meteoroid trajectories to analyze slow and curved orbits associated with artificial objects. To corroborate our results, we approximated the orbital elements for the upper stage using four pieces of "debris" cataloged by the U.S. Government Combined Space Operations Center (CSpOC). Based on these calculations, we also estimated the possible deorbit hazard zone using the MSISE90 model atmosphere. We warn of the interference that these artificial bolides might have in fireball studies. In addition, given that artificial bolides will be probably more frequent in the future, we point out the new role that ground-based detection networks can play in the monitoring of potentially hazardous artificial objects in near-Earth space and determining the strewn field of artificial space debris.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
