Method and means of electrical prospecting using analog models and electrode impedance cancelling apparatus

Claim 1

IN A METHOD FOR ELECTRICALLY LOCATING AND CHARACTERIZING SUBTERRANEAN GEOLOGICAL CHARACTERISTICS COMPRISING THE STEPS OF, (A) ESTABLISHING A REFERENCE COUPLING VOLTAGE AT A REFERENCE ELECTRODE BY ADJUSTING PHASE AND AMPLITUDE OF A POTENTIAL AT A POINT ADJACENT A CURRENT SOURCE TO EQUAL THE PHASE AND AMPLITUDE OF A POTENTIAL ACROSS THE REFERENCE COUPLING THEREBY CANCELING THE EFFECT OF ELECTRODE IMPEDANCE, (B) PASSING AN ELECTRICAL CURRENT AT A PLURALITY OF FREQUENCIES THROUGH A PLURALITY OF EARTH SECTIONS, (C) MEASURING THE TRANSFER IMPEDANCE AS A FUNCTION OF FREQUENCY, (D) PLOTTING THE MEASUREMENTS OF EACH EARTH SECTION, AND (E) COMPARING THE PLOTTED MAGNITUDES OF SAID TRANSFER IMPEDANCE AT AT LEAST ONE OF SAID FREQUENCIES OBTAINED AT ONE OF SAID SECTIONS WITH AT LEAST ONE OTHER OF SAID SECTIONS.