In South Korea, there are about 80 Global Positioning System (GPS) monitoring stations providing total electron content (TEC) every 10 min, which can be accessed through Korea Astronomy and Space Science Institute (KASI) for scientific use. We applied the computerized ionospheric tomography (CIT) algorithm to the TEC dataset from this GPS network for monitoring the regional ionosphere over South Korea. The algorithm utilizes multiplicative algebraic reconstruction technique (MART) with an initial condition of the latest International Reference Ionosphere-2016 model (IRI-2016). In order to reduce the number of unknown variables, the vertical profiles of electron density are expressed with a linear combination of empirical orthonormal functions (EOFs) that were derived from the IRI empirical profiles. Although the number of receiver sites is much smaller than that of Japan, the CIT algorithm yielded reasonable structure of the ionosphere over South Korea. We verified the CIT results with NmF2 from ionosondes in Icheon and Jeju and also with GPS TEC at the center of South Korea. In addition, the total time required for CIT calculation was only about 5 min, enabling the exploration of the vertical ionospheric structure in near real time.

• Junseok Hong(Department of Astronomy, Space Science and Geology, Chungnam National University, Daejeon 34134, Korea)
• Yong Ha Kim(Department of Astronomy, Space Science and Geology, Chungnam National University, Daejeon 34134, Korea) Corresponding Author
• Jong-Kyun Chung(Korea Astronomy and Space Science Institute, Daejeon 34055, Korea)
• Nicholas Ssessanga(Department of Astronomy, Space Science and Geology, Chungnam National University, Daejeon 34134, Korea)
• Young-Sil Kwak(Korea Astronomy and Space Science Institute, Daejeon 34055, Korea)