[P-EM15] Study of coupling processes in solar-terrestrial system

[PEM15-03] Latest activities of i-SPES & Kyutech FM-CW project: 2023

*Akiko Fujimoto¹, Shuji Abe², Akimasa Yoshikawa², Akihiro Ikeda³, Yuu Hiroshige¹, Hayato Nakamura¹, Yuki Goou¹ (1.Kyushu Institute of Technology, 2.Kyushu University, 3.National Institute of Technology, Kagoshima College)

Keywords:Ionospheric Observation

The ionosphere, from about 100km to high altitudes, has a significant impact on the radio propagation for communications, satellite positioning system, etc. The structure of ionosphere is not stable and variable in the time of day, season, latitude, and solar activity, because of the differences of the energetic photo-ionization process. The irregularities and disturbances in the ionosphere cause various severe problems, for example, lower accuracy of the radio navigation due to the global positioning system/Global Navigation Satellite System scintillation, disruptions in High Frequency (HF) radio wave bands or interferences due to anomalous propagation, etc. To utilize radio propagation safely and securely in modern society, it is essential to measure and analyze the fluctuating ionospheric environment at high speed and with high accuracy.

An FM-CW (Frequency Modulated Continuous Wave) radar is a type of HF (High Frequency) radar. We have installed and operated four FM-CW stations along the Japanese longitude, in Japan, Russia, Philippine, and Peru, to measure the electric fields penetrating the ionosphere. We have been developing the SDR (Software-Defined Radio)-based scintillation detector system integrated with FM-CW and MAGDAS (http://data.icswse.kyushu-u.ac.jp) projects. In this paper, we will present the following latest activities of our project: proposal of a new detection method of Ionogram echoes and latest status of development of software radio-GPS scintillation measurements.