Abstract
The usual plane wave assumption of a sufficiently uniform primary field is questionable at auroral and equatorial latitudes near localized ionospheric currents. Besides attempting to select only events with distant sources, it is reasonable to try to eliminate the distortion due to source effects by taking averages over several events. However, it is difficult to determine the best averaging method in the calculation of the apparent resistivity, the impedance phase, or the induction vector. In this paper, we use synthetic models to demonstrate the differences in averaging methods.
