Design of a Force Balance Geophone Utilizing Bandwidth Extension and Data Acquisition Interface

This paper reports on the design, simulation and hardware implementation of a force balance geophone comprising a high order ΣΔM with the proportional-integral-derivative (PID) feedback loop. The system is simulated and analyzed by Simulink modeling, and obtains a low-frequency and stable system. The prototype engages a conventional low cost 4.5 Hz SM-6 geophone cascaded by two distributed feedback (DF) electronic integrators for high-order noise shaping. Our resulting force balance geophone confirms an extended bandwidth to 0.16 Hz and a simulated NEA of 17 ng/√Hz. These performances shows its potential for highly effective and low-cost seismic exploration.