Bandwidth extension of a 4.5 Hz geophone for seismic monitoring purpose

Abstract

The devices usually employed for seismic monitoring have some limitations that prevent a complete characterization of the seismic signals, especially at the low frequency. In order to overcome such limitations we propose a relatively easy and low-cost device able to extend the bandwidth of a commercial 4.5 Hz geophone. The system basically consists in a operational amplifier with negative feedback, a buffer amplifier, and a numerical filter. The system has been specifically designed for the selected geophone, however, the idea can be easily applied to other similar devices. The low-cost of the system if compared to the manufactured expensive broadband sensor enables large-scale and/or high-density application with contained cost.