  In order to test gravitation in the Solar System, it is necessary to improve
the orbit restitution of interplanetary spacecrafts. The addition of an
accelerometer on board is a major step toward this goal because this instrument
measures the non-gravitational acceleration of the spacecraft. It must be able
to perform measurements at low frequencies with no bias to provide an
additional observable of interest.
  Since electrostatic accelerometers suffer a bias, a technological upgrade has
been proposed by Onera. It consists in adding to an electrostatic accelerometer
a rotating platform which allows modulating the signal of interest and
retrieving it without bias after post-processing. Using this principle, a
measurement method and a post-processing method have been developed. The
objective of this article is to validate these methods experimentally. To do
so, a horizontally controlled pendulum was used to apply a known signal to an
accelerometer mounted on a rotating platform. The processing of the
experimental data demonstrates the ability to make acceleration measurements
with no bias. In addition, the experimental precision on the unbiased
acceleration obtained after post-processing corresponds to the precision
predicted theoretically.
