林其彥Chi-Yen Lin 1*
1 國立中央大學太空科學與科技研究中心
*chiyen.lin1016@gmail.com
In recent decades, the development of space satellite missions has completely changed our
understanding of the natural environment. With the widespread use of space technologies
such as communication satellites and GNSS positioning in everyday life, along with various
countries actively developing their space industries, the impact of severe ionospheric space
weather changes on human life has become more significant than ever. Since FORMOSAT-
3/COSMIC and FORMOSAT-7/COSMIC-2 began providing extensive ionospheric radio
occultation electron density profile data, people have gained a better understanding of the
ionospheric plasma structure and explored its physical mechanisms. Several new findings,
including plasma depletion bays and vertical ionospheric disturbances caused by earthquakes
and tsunamis, have been reported using RO sounding. Although the RO sounding can provide
thousands of vertical observations per day, it still needs to gather several weeks of data to
construct the 3D structure of the ionosphere. Space weather events such as geomagnetic
storms or solar eclipses significantly impact the ionosphere but are rarely studied for their
effects on the 3D structure. Furthermore, Global Ionospheric Specification (GIS) uses the
Gauss-Markov Kalman filter to assimilate the total electron content (TEC) observed from
ground-based GNSS receivers and space-based RO instruments, providing a continuous 3D
electron density distribution of the ionosphere for improved study and monitoring of space
weather.
關鍵詞：Radio Occultation, FORMOSAT-3/COSMIC, FORMOSAT-7/COSMIC-2, Data
assimilation, Space Weather
