Patent ID: 7843768

Claim:
A system for the transmission of seismic waves through the earth comprising: a source of periodic, frequency-locked, unmodulated seismic energy comprising an oscillator for generating a signal, wherein the oscillator is a frequency-locked, electrical oscillator; an amplifier coupled to the oscillator; a transducer driven by the oscillator, wherein the transducer is an electromagnetic transducer comprising a first and a second magnet, wherein the first magnet is an electromagnet driven by the oscillator; an inertial mass coupled to the transducer, wherein the inertial mass's periodic movement caused by the transducer creates periodic seismic waves, wherein the inertial mass comprises the second magnet of the electromagnet and any structures attached to the second magnet that move relative to the transducer; a pressure plate coupled to the transducer for mounting to the earth; an adaptor engaging the transducer and attached to the pressure plate for conducting the seismic waves produced by the transducer to the pressure plate; a bearing system engaging the inertial mass and coupled to the pressure plate for limiting the inertial mass's off axis motion and providing a restoring force to the inertial mass; mounting brackets attached to the bearing system and attached to the pressure plate, wherein the mounting brackets are adjustable in order to modify the center of travel of the inertial mass; a receiver comprising a geophone coupled to the earth; a differential amplifier coupled to the geophone; a filter coupled to the differential amplifier; an amplifier coupled to the filter; an analog to digital converter coupled to the amplifier; a processing unit coupled to the analog to digital converter for frequency content identification of the signal, wherein the processing unit performs Fourier transforms in order to identify the power in all received signal frequencies.