Patent ID: 8670708

Claim:
A portable through-the-earth communication system using ultra-low-frequency modulated electric carrier waves for communicating with individuals below the earth's surface, said system comprising: a surface control unit; a first set of surface electrodes and a second set of surface electrodes spaced from one another and grounded, said first set and said second set of surface electrodes establishing an ultra-low-frequency electric current there between to transmit said ultra-low-frequency modulated electric carrier waves through the earth; a surface receiver for receiving said ultra-low-frequency modulated electric carrier waves from said first and second set surface electrodes, said surface receiver being connected to said first and second set of surface electrodes and in communication with said surface control unit; a surface transmitter for transmitting said ultra-low-frequency modulated electric carrier waves through the earth to a subsurface transceiver, said surface transmitter being connected to said first and second set of surface electrodes and in communication with said surface control unit; wherein said subsurface transceiver is connected to at least one set of subsurface electrodes and is in communication with said surface transmitter for receiving said ultra-low-frequency modulated electric carrier waves; wherein said subsurface transceiver is in communication with said surface receiver and said surface control unit to transmit said ultra-low-frequency modulated electric carrier waves through the earth to said surface receiver; and wherein said at least one subsurface electrode is disposed within the earth, and beneath the earth's surface.