An apparatus includes a seismic acquisition system that includes an
accelerometer. The accelerometer includes a capacitive MEMS-based sensor,
a controller and a charge amplifier. The sensor includes a proof mass;
input terminals to receive a first signal; and an output terminal that is
electrically connected to the proof mass to provide a second signal. The
first signal, which is regulated by the controller, controls an
equilibrium restoring force for the sensor and causes the sensor to
provide the second signal. The charge amplifier provides a third signal,
which is indicative of a position of the proof mass. The charge amplifier
has an input terminal to continuously receive the second signal during a
time in which the first signal controls the equilibrium restoring force
and causes the sensor to provide the second signal