Quantitatively estimating magnetotail flapping motion is critical for understanding and characterizing its dynamical behaviors. Such estimation can be achieved in principle by the multipoint analysis of spacecraft tetrahedron, for example, Cluster or MMS mission, but, owing to the inability of single‐point measurement to separate the spatial‐temporal variation of magnetic field, would be inadequate for a single spacecraft. Since single‐point missions dominate explorations of planetary magnetotail, we have developed a single‐point method based on the magnetic field measurement that quantitatively estimates the parameters of flapping motion, including spatial amplitude, wavelength, and propagation velocity. By comparing several applied cases with the multipoint analysis of Cluster, we demonstrate that our method can be reasonably applied to infer the average parameters over the whole flapping period when magnetotail is during quiet phase (magnetic field in magnetotail does not experience significant temporal variation). Thus, this method could be applied widely to the “big data set” accumulated by single‐point spacecraft missions in order to study magnetotail flapping dynamics.

中文翻译：

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定量诊断磁尾扑动的单点方法

定量估计磁尾扑动对于理解和表征其动力学行为至关重要。原则上，可以通过航天器四面体的多点分析（例如，簇或MMS任务）来实现这种估计，但是由于无法进行单点测量来分离磁场的时空变化，因此这种估计是不够的。单飞船。由于单点任务在行星磁尾的探索中占主导地位，因此我们基于磁场测量开发了一种单点方法，该方法可以定量估计拍打运动的参数，包括空间振幅，波长和传播速度。通过将几个应用案例与Cluster的多点分析进行比较，我们证明，当磁尾处于安静阶段（磁尾中的磁场没有明显的时间变化）时，我们的方法可以合理地用于推断整个拍打期间的平均参数。因此，该方法可广泛应用于单点航天器飞行任务积累的“大数据集”，以研究磁尾扑动动力学。