Читать книгу Global Navigation Satellite Systems, Inertial Navigation, and Integration - Mohinder S. Grewal - Страница 108

The WGS84 Earth model approximates mean sea level (an equipotential surface) by an ellipsoid of revolution with its rotation axis coincident with the rotation axis of the Earth, its center at the center of mass of the Earth, and its prime meridian through Greenwich. Its semimajor axis (equatorial radius) is defined to be 6 378 137 m, and its semiminor axis (polar radius) is defined to be 6 356 752.3142 m.