Geophysical survey systems using polarized electromagnetic waves

Claim 1

IN A GEOPHYSICAL SURVEY SYSTEM, TRANSMITTER AND RECEIVER SECTIONS LOCATED AT HORIZONTALLY SPACED POINTS RELATIVE TO THE EARTH''S SURFACE, SAID RECEIVER SECTION INCLUDING AN ANTENNA AND AMPLIFIER AND DETECTOR MEANS COUPLED TO SAID ANTENNA, SAID TRANSMITTER SECTION INCLUDING A TRANSMITTER, AT LEAST ONE MAIN ANTENNA COUPLED TO SAID TRANSMITTER AND ARRANGED TO TRANSMIT HORIZONTALLY POLARIZED WAVES INTO THE EARTH, AND MEANS FOR NEUTRALIZING THE EFFECT OF WAVES TRANSMITTED FROM SAID MAIN TRANSMITTING ANTENNA TO SAID RECEIVING ANTENNA INCLUDING AN AUXILIARY TRANSMITTING ANTENNA ARRANGED TO EMANATE VERTICALLY POLARIZED WAVES, AMPLIFIER AND PHASE SHIFTER MEANS IN SAID TRANSMITTEER SECTION ARRANGED TO APPLY A SIGNAL FROM SAID TRANSMITTER TO SAID AUXILIARY ANTENNA, AND MEANS FOR ADJUSTING SAID AMPLIFIER AND PHASE SHIFTER MEANS TO PRODUCE A MINIMUM OUTPUT FROM SAID RECEIVER DETECTOR MEANS.