Measurements and mobiles
Measuring the Earth's gravity field

We have already seen that relative gravity measurements can be taken at fixed points. It may be interesting to carry out continuous measurements on the move, on ships or aircraft for example.

Gravity meters installed on stabilized platforms are used. But two problems arise:

• the moving body on which measurements are taken is in motion relative to the frame of reference linked to the Earth's center of mass;

• the mobile may be subject to significant parasitic accelerations (e.g. pitching on a boat).

Around 1908, R. von Eötvös showed that a correction had to be applied to the measurements to take account of the fact that the moving body is moving relative to the earth's reference frame. This movement induces both a centripetal and a Coriolis acceleration....