mean Earth ellipsoid
Earth ellipsoid or Earth spheroid that is a mathematical figure approximating the Earth's form, used as a reference frame for computations in geodesy, astronomy, and the geosciences, Maa ellipsoid või Maa sferoid, mis on Maa vormi ligikaudne matemaatiline mudel, mida kasutatakse geodeesia, astronoomia ja geoteaduste arvutustes tugiellipsoidina