TEC derived from some GPS stations in Nigeria and comparison with the IRI and NeQuick models

• Total electron content (TEC) were estimated from GPS observables recorded simultaneously at six locations in Nigeria.
• The observed TEC exhibits features like the daytime maximum, diurnal variation, seasonal variation and semiannual variations.
• IRI model produced better estimates of TEC than NeQuick at all locations.

Total electron content (TEC) measured simultaneously using Global Positioning System (GPS) ionospheric monitors installed at some locations in Nigeria during the year 2011 (Rz = 55.7) was used to study the diurnal, seasonal, and annual TEC variations. The TEC exhibits daytime maximum, seasonal variation and semiannual variations. Measured TEC were compared with those predicted by the improved versions of the International Reference Ionosphere (IRI) and NeQuick models. The models followed the diurnal and seasonal variation patterns of the observed values of TEC. However, IRI model produced better estimates of TEC than NeQuick at all locations.