We propose an application of the independent component analysis (ICA) to separate satellite‐induced time‐varying stray fields from magnetic field data obtained using onboard multiple magnetometers. The ICA is a method for estimating source signals at multiple sites so that the estimated source signals can become statistically independent of each other. Since stray field variations are statistically independent of external natural field variations, the ICA method is expected to separate the natural variations from stray fields. Thus, we applied the ICA to magnetic field data from the first Quasi‐Zenith Satellite, which has two triaxial fluxgate magnetometers, without using an extendable boom. First, we removed the long‐period trend from the original data to create detrended data. Then, we applied the FastICA algorithm to the detrended data and obtained six independent components (ICs). The stray fields were successfully separated into three ICs (noise ICs), and the natural signals were represented by the other three ICs (signal ICs). Finally, we restored the observed signals from the signal ICs, and confirmed that the natural phenomena variations were not altered by the processing step. We also proposed a selection method of the noise ICs using the C coefficient, which is the coefficient of the variance of the mixing vectors. There was a large difference in C between the ICs whose C coefficients are the largest third and fourth ones. Overall, these results demonstrate the possibility that the ICA method can support for boom‐less magnetic observations in future satellite missions.

中文翻译：

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通过独立分量分析从卫星磁场数据中分离信号和噪声：没有动臂和噪声源信息的磁测量前景

我们建议应用独立分量分析（ICA）来将卫星感应的时变杂散场与使用机载多个磁力计获得的磁场数据分开。ICA是一种用于估计多个站点上的源信号的方法，以使所估计的源信号在统计上变得彼此独立。由于杂散场变化在统计上与外部自然场变化无​​关，因此，ICA方法有望将自然变化与杂散场分开。因此，我们将ICA应用于第一颗准Zenith卫星的磁场数据，该卫星具有两个三轴磁通门磁强计，而没有使用可伸缩的吊杆。首先，我们从原始数据中删除了长期趋势，以创建去趋势数据。然后，我们将FastICA算法应用于去趋势数据，并获得了六个独立的分量（IC）。将杂散场成功地分为三个IC（噪声IC），自然信号由其他三个IC（信号IC）表示。最后，我们从信号IC中恢复了观察到的信号，并确认自然现象的变化没有被处理步骤改变。我们还提出了使用以下方法选择噪声IC的方法：C系数，它是混合向量方差的系数。C系数最大的第三和第四IC之间的C差异很大。总体而言，这些结果表明，ICA方法有可能支持未来卫星任务中的无动臂磁观测。