Contributions to model characterization of geophone sensor

In an oceanographic campaign of seismic prospecting it is often needed equipments with geophones to measure the motion of the sea bed. Normally, the signal is weak compared to the noise because the source is a few kilometres away from the sensor. The noise is due to the ambient in the ocean (seismic activity, currents, etc) and the electronic noise in the equipment (sensor, amplifier stage, A/D converter, hard disc and connexions). In order to characterize the electromagnetic geophone sensor and the performance with amplifier stage we have found models of a geophone sensor and we have simulated them with different amplifiers to improve the ratio S/N.