Global Gravity Field Models

Synonyms

Global geopotential model; Global gravity field model; Global model

Definition

In geodesy, a global gravity field model means a mathematical function which describes the gravity field of the Earth in the three-dimensional space. The determination of the Earth’s global gravity field is one of the main tasks of geodesy: it serves as a reference for geodesy itself, and it provides important information about the Earth, its interior, and its fluid envelope for all geosciences.

Gravitation Versus Gravity

According to Newton’s law of gravitation (Newton 1687), the magnitude of the attracting force F between two point-shaped masses m₁ and m₂ is

$$ F=G\frac{m_1{m}_2}{l^2} $$

(1)

where l is the distance between the two masses, and G is the gravitational constant. The vector of the attracting force of a body with the density ρ in the volume v acting onto a point-shaped sample mass m at the point P is given by the volume integral:

$$ \overrightarrow{F}(P)= Gm\underset{v}{\int}\frac{\rho...