Clairaut's formula

Clairaut's formula [′kler·ȯz ‚fȯr·myə·lə]

(geodesy)

An approximate formula for gravity at the earth's surface, assuming that the earth is an ellipsoid; states that the gravity is equal tog_e[1+(⁵⁄₂m'-f) sin²θ], where θ is the latitude,g_eis the gravity at the equator,m′is the ratio of centrifugal acceleration to gravity at the equatorial surface, andfis the earth's flattening, equal to (a-b)/a, whereais the semimajor axis andbis the semiminor axis.