Gravimetry
The Earth’s gravity field influences practically all geodetic measurements and thus always has to be taken into account. It is determined with the aid of gravimetric measurements.
A distinction is made between absolute and relative methods of gravimetric measurement. Today, absolute gravimeters operate exclusively on the basis of the free-fall method, whereas relative gravimeters function on the basis of the spring-balance principle.
The direction of the gravity vector (vertical deflection) can be determined using astronomical methods.