Geostationary orbit is a high altitude Earth orbit, where the speed of the satellite around the Earth can follow the speed of the Earth’s rotation. Situated at an altitude of 35,786 kilometers above the equator, it is an ideal location for weather forecasting, communications and ground monitoring.
Satellites orbit the Earth in one of three basic orbits defined by altitude from the ground: low Earth orbit, medium Earth orbit, or high Earth orbit. The higher the orbit of the satellite, the lower its speed of movement. Indeed, Earth’s gravity exerts a stronger attraction on satellites closer to the ground than on satellites further away.
Satellites in low Earth orbit, such as the International Space Station, located about 400 km above the ground, will move relative to the ground to see different regions at different times together. Satellites in medium Earth orbit (between 2,000 and 35,780 km) move more slowly, allowing more detailed research of Earth’s regions. In geostationary orbit (high Earth orbit), the rotation period of the satellite around the Earth is exactly 24 hours, and the satellite therefore appears to remain in the same position in longitude, but its orbit may be tilted a few degrees towards the north or towards the north. South.
Advantage
A satellite in geostationary orbit can see the same area on the ground most of the time. For Earth observation, this allows satellites to observe changes in a region over a period of months or years. The obstacle here is the limitation of satellites to only observe a small part of the ground: if a disaster occurs somewhere, the satellite cannot move there due to fuel problems.
But it is an advantage for the military field. For example, when U.S. authorities are concerned about activities in a certain region of the world or want to see the military situation in a certain area, geostationary satellites can take still or monitored photos in a certain area. The American SATCOM 5 satellite launched in 2013 is a typical example of the surveillance role of this type of satellite. Combined with four other SATCOM satellites, to create a military communications system providing virtually global coverage. Such satellite networks can be used by the military, ships, drones or government officials, and can also be used to provide communications for government organizations or employees.
Another benefit of geostationary orbit is communications. A large number of companies specialize in transmitting telephones, Internet, television and other equipment via geostationary satellites. Since the satellite remains fixed over an area, communication to that location can be maintained for a long time as the satellite connectivity to that area is always stable.
Orbital competition
According to Satellite Signals company records, there are currently approximately 402 satellites in geostationary orbit. The geostationary orbit is likened to a “ring” of the Earth that can accommodate up to 1,800 satellites at a time, according to an analysis by Lawrence Roberts, published in Berkeley Technology Law Review. However, many limitations remain in the field of space technology.
In particular, satellites must maintain a stable area in orbit, without straying too far from their assigned position, otherwise they could pose a threat to other satellites. The International Communications Union will regulate positions in geostationary orbit and arbitrate disputes between countries regarding positions in orbit.
Likewise, it is necessary to move damaged satellites to a “graveyard” orbit before they run out of fuel and to pave the way for next-generation satellites.
And the satellites must be far enough apart so that their communication signals do not interfere with each other, more precisely, they must be spaced about 1 to 3 degrees apart. With improving technology, it is possible to pack many satellites into a small space
According to: VLTV – Source: Space.com
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