The microgravimetric method consists in determining with high precision the variation of the gravitational field in a certain region.
Instead of the traditional gravitymeters (with a resolution of 5-10 microgal) last generation microgravitymeters with greater sensitivity available in the market are used nowadays (1-2 microgal).
The field campaign is carried out occupying distributed measurement stations in profiles or in regular mesh that covers all the region of interest. In addition it is necessary to obtain periodic readings (every half an hour) in a reference point (denominated base) to obtain the curve of instrumental drift.
After obtaining the field data, and applying the necessary corrections (instrumental drift, tides, topography, etc) density models of the ground are generated. It is generally a method used in gallery and void detection (that suppose a mass deficit with respect to the surrounding ground).