Fig. 2.From: Hodograph method to estimate the latitudinal profile of the field-line resonance frequency using the data from two ground magnetometersIllustrates the model hodograph R m (Eq. (5)) based on the FLR theory, plotted on the complex plane. The hodograph, with the assumption that the resonance width δ is a constant, is a circle. See text for more details.Back to article page