[P-EM14] 太陽地球系結合過程の研究基盤形成

[PEM14-P16] Development of a Real-Time Ionospheric Scintillation Monitoring System Using SDR

*藤本 晶子¹、中村 駿仁¹、阿部 修司²、吉川 顕正²、池田 昭大³、牛王 悠輝¹、吉野 郁海¹、成合 秀飛¹ (1.九州工業大学、2.九州大学、3.鹿児島工業高等専門学校)

キーワード：電離圏シンチレーション、ソフトウェア無線、リアルタイム監視

The ionosphere, ranging from 100 km to 1000 km in altitude, exhibits significant fluctuations due to solar activity, affecting GNSS positioning accuracy and radio wave propagation. To mitigate these effects, we developed a continuous ionospheric monitoring system using Software-Defined Radio (SDR) technology. The system consists of GNSS signal reception hardware and software for real-time ionospheric data processing. Key requirements include system miniaturization and cost reduction, remote control of observation units, continuous GNSS positioning with five-minute interval data processing, and real-time calculation and visualization of the S₄ index, which quantifies scintillation intensity. A previous study successfully reduced hardware costs by 60% compared to the initial prototype.

To enable remote control, we integrated Chrome Remote Desktop to the system for stable internet-based access. GNSS-SDR, an open-source software, facilitates automated GNSS positioning and data acquisition. The system separately stores GNSS signal strength and navigation message data, enabling real-time computation of the S₄ index. Visualization includes S₄-sky plots displaying satellite positions and time-series S₄ index variations, ensuring comprehensive monitoring of ionospheric disturbances.

We confirmed the system's ability to detect ionospheric fluctuations through S₄ index variations. The system is now in continuous operation for long-term ionospheric scintillation monitoring. These findings contribute to advancing digital processing techniques for radio wave propagation and may support the digitalization of analog ionospheric radar systems, such as ionosondes.