Fig. A.1.From: Hodograph method to estimate the latitudinal profile of the field-line resonance frequency using the data from two ground magnetometersShows a solution for the FLR equation by Southwood (1974) (dashed line) and Eq. (1) in the same format as Fig. 1. The vertical dashed lines corresponds to the valid, or differently put, precise-enough range of Eq. (1), given by Eq. (24). See text for more details.Back to article page