Figures One and Two are a presentation of data from a single line of pole-dipole IP (200m a-spacing) from South America. High electrode impedances and resultant low injected currents in caliche-covered ground usually results in poor data quality. The G.R.S. *telluric cancellation procedure records telluric events at a remote location and then removes them from the I.P. data in real-time. This typically results in improvement in S/N by a factor of 5-6.
In the pseudosections above the ‘grain’ of the pole-dipole data dominates after telluric cancellation, but is less clear amongst the antithetical telluric ‘grain’.
At the individual decay level the effect is even more striking, 3 separate readings (at n=12.5) are plotted before and after the telluric cancellation process