Digital electronics for electrostatic accelerometers interest for high resolution and in-orbit calibration

The new ultra-sensitive space accelerometers to come are designed to . demonstrate a level of noise below 10-12 m s-2 √Hz .This performance requires in- orbit calibration. For example, calibration consists in proof mass fine positioning and scale factor measurement. Working out these tasks of calibration is more relevant. to digital electronics than to the present analog ones. The challenge for such a substitution is to preserve the wide dynamic of electrostatic accelerometers, and so maintain the performance calculated for the present, purely analog design. A prototype has been developed and tested at ONERA and the results are discussed here in terms of constraints upon calibration.