(a) Map of Nigeria showing the IPP tracks of PRNs that detected the 0.52 mHz wave 2000–2100 UT, 17 June 2022. The IPP tracks are progressing northwards. (b), (c), (d), (e) and (f) are the filtered sTEC from LAGO (PRN 7), ASDE (PRN 7), PHRI (PRN 7), CBCR (PRN 7), and YLAD (PRN 30), respectively, during the interval 2000–2100 UT, 17 June 2022. The red markers in the time series are inserted to assist in visualizing the phase progression of the wave.