The satellite which appears at rest when observed from any location of earth is called geostationary satellite. Following conditions must be fulfilled by a satellite to be geostationary:
- The time period of the satellite around the earth must be equal to the rotational period of the earth about its own axis (i.e. 24 hours).
- The direction of motion of the satellite must be same as that of the earth.
- The height of geostationary satellite from earth’s surface must be about 36000 km.
- The plane of the orbit of that satellite should be in the same plane as the equatorial plane.
- The centre of the circle formed by the motion of the satellite and the earth’s centre should also be coincident.