Research on Global Ionospheric TEC Deep Learning Forecasting Based on Spectral Whitening Method Index Group
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摘要: 全球电离层总电子含量(TEC)的时空变化直接影响全球导航卫星系统(GNSS)的定位精度和通信系统可靠性. 针对传统太阳活动与地磁指数时间分辨率低、更新不及时, 限制极端空间天气条件下数据驱动预报性能的问题, 提出基于白谱法(SWM)的物理驱动指数群, 引入高纬扰动指数表征日地能量耦合过程, 并结合深度神经网络与3D Swin Transformer构建三维电子密度重构和时空预报两阶段框架. 结果表明, SWM指数与传统指数保持高度相关, 其高频物理特征可加快模型收敛、提高稳定性; SWM驱动模型显著优于IRI-2020经验模型, 并能抑制长时效预报的误差累积. 该指数群具有较强的实时更新和扰动捕捉能力, 可为高性能、业务化全球空间天气预报提供新的技术路径.
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关键词:
- 全球电离层 /
- 总电子含量(TEC) /
- 白谱法(SWM) /
- 深度学习
Abstract: The spatiotemporal evolution of global ionospheric Total Electron Content (TEC) directly affects the positioning accuracy of Global Navigation Satellite Systems (GNSS) and the reliability of communication systems. Accurate TEC prediction is therefore essential for space weather research and operations. Most existing ionospheric forecasting models use conventional solar activity and geomagnetic indices, such as F10.7, Kp, and Dst, as external drivers. Their relatively low temporal resolution and infrequent updates make it difficult to represent rapid energy transfer and disturbance processes, which can constrain data-driven forecasts during extreme space weather events. To overcome this limitation, this study develops a physically driven index group using the Spectral Whitening Method (SWM). The SWM procedure suppresses periodic background components and emphasizes non-stationary disturbances. A high-latitude disturbance index is further incorporated so that the index group can characterize the chain of solar-terrestrial energy coupling from solar energy input to geomagnetic and ionospheric responses. The index group is evaluated within a two-stage deep learning forecasting framework. In the first stage, a deep neural network reconstructs three-dimensional electron density; in the second stage, a 3D Swin Transformer learns the spatiotemporal evolution and produces global TEC forecasts. The SWM-driven model is compared with the same framework driven by conventional indices and with the IRI-2020 empirical model. Results show that the SWM indices retain high statistical correlations with conventional indices while providing higher-frequency physical information. These properties accelerate model convergence and improve training stability. The SWM-driven model achieves better forecasting performance than IRI-2020 and exhibits stronger error-control capability under disturbed conditions. It also reduces the accumulation of errors in longer lead-time forecasts, indicating that the SWM index group supplies useful real-time physical constraints for deep learning. The findings demonstrate that jointly representing solar, geomagnetic, and high-latitude disturbance information can improve the responsiveness and robustness of global ionospheric forecasting. With its rapid updating capability and sensitivity to transient disturbances, the proposed index group provides a practical technical pathway toward high-performance and operational global space weather prediction. -
表 1 第一阶段DNN的超参数设置
Table 1. Hyperparameter configuration for the first-stage DNN
参数名称 参数值 Input dimension 12 Hidden layer dimensions [512, 256, 128, 64, 16] Output dimension 1 Batch size 32768
××
16Optimizer Adam Loss function RSE loss Learning rate $ 1\times {10}^{-2} $ Epochs 100 表 2 第二阶段时空演化模块(3D Swin Transformer)的超参数设置
Table 2. Hyperparameter configuration for the second-stage spatiotemporal evolution module (3D Swin Transformer)
参数名称 参数值 Embedding dimension 96 Number of attention heads [4, 6, 12, 24] Block size 168 Batch size 4 Optimizer AdamW Loss function RSE loss Learning rate $ 1\times {10}^{-4} $ Epochs 100 表 3 2019年DOY 90~96地磁平静期间不同模型的平均预报性能对比
Table 3. Comparison of mean forecast performance among different models during the geomagnetic quiet period of DOY 90-96, 2019
指数驱动模型 R2 MAD/TECU RMSE/TECU SWM指数群驱动 0.888 1.442 2.201 传统指数群驱动 0.891 1.433 2.162 IRI-2020 0.697 2.966 3.61 表 4 2018年3月磁暴期间不同模型的平均预报性能对比
Table 4. Comparison of mean forecast performance among different models during the March 2018 geomagnetic storm
指数驱动模型 R2 MAD/TECU RMSE/TECU SWM指数群驱动 0.902 1.614 2.477 传统指数群驱动 0.896 1.696 2.532 IRI-2020 0.788 2.699 3.680 -
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孙嘉豪 男, 2001年出生于江西省九江市, 现为南昌大学信息工程学院人工智能专业硕士研究生, 主要研究方向为基于深度学习的全球电离层预报、白谱法指数在空间天气中的应用等. E-mail:
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