A through-the-earth communication system that includes a digital signal
input device; a transmitter operating at a predetermined frequency
sufficiently low to effectively penetrate useful distances through-the
earth; a data compression circuit that is connected to an encoding
processor; an amplifier that receives encoded output from the encoding
processor for amplifying the output and transmitting the data to an
antenna; and a receiver with an antenna, a band pass filter, a decoding
processor, and a data decompressor.