<P> Geostationary satellites are directly overhead at the equator and appear lower in the sky to an observer nearer the poles . As the observer's latitude increases, communication becomes more difficult due to factors such as atmospheric refraction, Earth's thermal emission, line - of - sight obstructions, and signal reflections from the ground or nearby structures . At latitudes above about 81 °, geostationary satellites are below the horizon and cannot be seen at all . Because of this, some Russian communication satellites have used elliptical Molniya and Tundra orbits, which have excellent visibility at high latitudes . </P> <P> Satellites in geostationary orbit must all occupy a single ring above the equator . The requirement to space these satellites apart to avoid harmful radio - frequency interference during operations means that there are a limited number of orbital "slots" available, and thus only a limited number of satellites can be operated in geostationary orbit . This has led to conflict between different countries wishing access to the same orbital slots (countries near the same longitude but differing latitudes) and radio frequencies . These disputes are addressed through the International Telecommunication Union's allocation mechanism . In the 1976 Bogotá Declaration, eight countries located on the Earth's equator claimed sovereignty over the geostationary orbits above their territory, but the claims gained no international recognition . </P> <P> A geostationary orbit can be achieved only at an altitude very close to 35,786 km (22,236 mi) and directly above the equator . This equates to an orbital velocity of 3.07 km / s (1.91 mi / s) and an orbital period of 1,436 minutes, which equates to almost exactly one sidereal day (23.934461223 hours). This ensures that the satellite will match the Earth's rotational period and has a stationary footprint on the ground . All geostationary satellites have to be located on this ring . </P> <P> A combination of lunar gravity, solar gravity, and the flattening of the Earth at its poles causes a precession motion of the orbital plane of any geostationary object, with an orbital period of about 53 years and an initial inclination gradient of about 0.85 ° per year, achieving a maximal inclination of 15 ° after 26.5 years . To correct for this orbital perturbation, regular orbital stationkeeping manoeuvres are necessary, amounting to a delta - v of approximately 50 m / s per year . </P>

The orbital speed of geo stationary satellite is