Fig. 19From: Double-thin-shell approach to deriving total electron content from GNSS signals and implications for ionospheric dynamics near the magnetic equatorTEC results by different methods. a and b Double-shell model applied to preprocessed slant TEC by method A, c–e double-shell model applied to preprocessed slant TEC by method B, and (f) two-step approach (method C). g–k difference between TEC maps on the left and the reference (panel a)Back to article page