Table 1. Geographical and geomagnetic coordinates of ionosonde observatory around the Korean Peninsula

Satation	Geographic latitude (°N)	Geographic longitude (°E)	Geomagnetic latitude (IGRF-13(2022), °N)	Geomagnetic longitude (IGRF-13(2022), °E)
Wakkanai	45.16	141.75	37.27	210.08
Beijing	40.30	116.20	31.17	187.89
Icheon	37.14	127.54	28.32	198.24
Kokubunji	35.71	139.49	26.67	209.23
Jeju	33.43	126.30	24.55	197.36
Yamagawa	31.20	130.62	22.55	201.49
Wuhan	30.50	114.40	21.22	186.53