System Identification of Local Time Electron Fluencies at Geostationary Orbit
System Identification of Local Time Electron Fluencies at Geostationary Orbit
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DOI：
10.1029/2020ja028262
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发表时间：
2020-11
期刊：
影响因子：
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通讯作者：
R. Boynton;Homayon Aryan;A. Dimmock;M. Balikhin
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文献类型：
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作者：
R. Boynton;Homayon Aryan;A. Dimmock;M. Balikhin
利用系统辨识技术对GOES 13、14和15卫星测量的地球静止轨道电子通量进行了建模。系统识别，类似于机器学习，使用输入输出数据来训练模型，然后可以用来提供预测。本研究采用非线性自回归滑动平均外生技术推导电子通量模型。已知地球静止轨道上的电子通量在空间和时间上变化，使其成为时空系统，这使得使用系统识别/机器学习方法的建模变得复杂。因此，电子通量数据被分箱到24个磁本地时间（MLT）中，并为24个MLT箱中的每个箱开发单独的模型。为GOES 13、14和15电子通量能量通道（75 keV、150 keV、275 keV、475 keV、>800 keV和>2 MeV）中的六个开发MLT模型。通过预测效率（PE）和相关系数（CC）在单独的测试数据上对模型进行评估，发现这些随MLT和电子能量而变化。在午夜扇区的75 keV的最低能量具有36.0的PE和59.3的CC，其在白昼侧增加到66.9的PE和81.6的CC。这些指标增加到>2 MeV的模型，其在夜侧具有63.0和81.8的低PE和CC，在昼侧具有80.3和90.8的高PE和CC。
The electron fluxes at geostationary orbit measured by Geostationary Operational Environmental Satellite (GOES) 13, 14, and 15 spacecraft are modeled using system identification techniques. System identification, similar to machine learning, uses input‐output data to train a model, which can then be used to provide forecasts. This study employs the nonlinear autoregressive moving average exogenous technique to deduce the electron flux models. The electron fluxes at geostationary orbit are known to vary in space and time, making it a spatiotemporal system, which complicates the modeling using system identification/machine learning approach. Therefore, the electron flux data are binned into 24 magnetic local time (MLT), and a separate model is developed for each of the 24 MLT bins. MLT models are developed for six of the GOES 13, 14, and 15 electron flux energy channels (75 keV, 150 keV, 275 keV, 475 keV, >800 keV, and >2 MeV). The models are assessed on separate test data by prediction efficiency (PE) and correlation coefficient (CC) and found these to vary by MLT and electron energy. The lowest energy of 75 keV at the midnight sector had a PE of 36.0 and CC of 59.3, which increased on the dayside to a PE of 66.9 and CC of 81.6. These metrics increased to the >2 MeV model, which had a low PE and CC of 63.0 and 81.8 on the nightside to a high of 80.3 and 90.8 on the dayside.