Gravity meters, These instruments record variations
in Earth’s gravitational field, at ground level, which
are used to detect density contrasts within the Earth.
We use geodetic-grade GPS
(real-time and post-processed) to achieve centimeter
positioning accuracy for all gravity measurements.
Gravity varies with latitude, elevation, geology and time.
Gravity field models are used to compute a geoid
model, which can be used a reference for a vertical datum