EQUATORIAL ORBIT

An equatorial orbit generally known as geosynchronous orbit. An orbit around the Earth with an orbital period matching the Earth's sidereal rotation period. Synchronization means that for an observer at a fixed location on Earth, a satellite in a geosynchronous orbit returns to exactly the same place in the sky at exactly the same time each day.

In principle, any orbit with a period equal to the Earth's rotational period is technically geosynchronous, however, the term is almost always used to refer to the special case of a geosynchronous orbit that is circular (or nearly circular) and at zero (or nearly zero) inclination, that is, directly above the equator.

Geosynchronous Equatorial Orbit:

Geostationary orbit.

Sometimes called a geostationary orbit. A circular geosynchronous orbit in the plane of the Earth's equator has a radius of approximately 42,164 km (from the center of the Earth). A satellite in such an orbit is at an altitude of approximately 35,786 kilometers above mean sea level and has 24 hour orbit period.

It will maintain the same position relative to the Earth's surface. A perfect stable geostationary orbit is an ideal that can only be approximate. This is because, the satellite will drift out of this orbit (because of perturbations such as the solar wind, radiation pressure, variations in the Earth's gravitational field, and the gravitational effect of the Moon and Sun), and thrusters are used to maintain the orbit in a process known as station-keeping. The satellite visible from 1/3 Earth’s surface, so three satellite are needed for full coverage of the Earth.

Geostationary satellite.

Geostationary satellite at the geosynchronous orbit.