# Earth Gravity Models
Spherical-harmonic Earth gravity ([Montenbruck & Gill 2000](../guide/references.md#montenbruck2000), ยง3.2, Eq. 3.33) from the ICGEM coefficient files ([Ince et al. 2019](../guide/references.md#ince2019)) of EGM96 ([Lemoine et al. 1998](../guide/references.md#lemoine1998)), JGM-2 ([Nerem et al. 1994](../guide/references.md#nerem1994)), JGM-3 ([Tapley et al. 1996](../guide/references.md#tapley1996)) and ITU_GRACE16 ([Akyilmaz et al. 2016](../guide/references.md#akyilmaz2016)).
::: satkit.gravmodel
::: satkit.gravity
::: satkit.gravity_and_partials