Sensitivity and resolution

An inevitable consequence of gravity gradient being the derivative of gravity is that there is much more signal power in the shorter wavelength (high frequency) of the gravity gradient signal. This allows for much better resolution of subsurface geology, the ultimate goal for any exploration program.

Gravity Gradiometry is also better suited to a moving platform. The inertial acceleration (movement from a plane/ship) seen by two (or more) accelerometers needed to perform the gradient measurement, is not present in the gravity gradiometry output. Inertial accelerations are common to both accelerometers and are intrinsically rejected.

For conventional gravity measurement the inertial acceleration is the dominant signal in the instrument output. The means for correcting this is by using GPS, which is only good for long wavelengths. Conventional gravity does not measure the short wavelength information with any acceptable level of accuracy. Therefore geological resolution is reduced.

Simplified view of Gravity and Gravity Gradiometry Measurements

Click play to see the effect of turbulence on data.