Fig. 2

Plots of apparent resistivity values (y-axis) against distance along transect (x-axis). The individual lines represent the raw apparent resistivity values (here at frequencies 12 and 25 KHz) for each replicate. The top panel was obtained when flying at the target actual altitude of 90 m, whilst the bottom panel at 65m. The black line represents the modelled mean in apparent resistivity for the Weiner Process model detailed in Section “Approach 1 - Weiner process”. Straight sections of the line in Replicate 1 are due to missing data. From these two plots it appears that the lower altitude (bottom panel) has less variability between replicates (i.e. is more repeatable) than the higher altitude (top panel)