Effects of St Patrick’s Day Intervals Geomagnetic Storms on the Accuracy of GNSS Positioning and Total Electron Content over Nigeria

Abstract

Total electron content (TEC) and GNSS positioning error over two Nigeria GNSS stations (CLBR: Latitude; 4.9503^°E, Longitude; 8.3514^°N, FUTY: Latitude; 9.3497^°E, Longitude; 12.4978^°N) were studied during the geomagnetic storms of March 17, 2015 minimum Dst (Disturbed storm time) -223nT and that of March 17, 2013 minimum Dst of -132nT (the St. Patrick's Day intervals); TEC was estimated using GPS Gopi TEC analysis software over the two stations during the storms period and the selected international quiet day used as reference. Understanding TEC variation in the equatorial ionosphere during geomagnetic storm will enable adequate prediction of GNSS positioning accuracy and correction over the region. Variation and enhancement of TEC were observed during the storms. The positioning error and TEC were higher at CLBR than at FUTY during the March 17, 2015 storm that could be as a result of latitudinal variation. The result will be useful for satellite based navigational systems.