Читать книгу Global Navigation Satellite Systems, Inertial Navigation, and Integration - Mohinder S. Grewal - Страница 105

Gravitational potential of a unit of mass is defined to be zero at a point infinitely distant from all massive bodies and to decrease toward massive bodies such as the Earth. That is, a point at infinity is the reference point for gravitational potential.

In effect, the gravitational potential at a point in or near the Earth is defined by the potential energy lost per unit of mass falling to that point from infinite altitude. In falling from infinity, potential energy is converted to kinetic energy, where is the escape velocity. Escape velocity at the surface of the Earth is about 11 km/s.