LEO is short for Low Earth Orbit Satellites.
As the name suggests, LEO satellites are closer to the earth than traditonal satellites.
There are actually four types satellite orbit.
The four types are:
Low Earth Orbit
Medium Earth Orbit
Geosynchronous Orbit
Geostationary Orbit.
Lets first look at Geosynchronous and Geostationary satellite orbits.
A satellite in a Geosynchronous orbit will only be ‘visable’ once a day.
This is because the Geosynchronous satellite does not stay in a fixed location, in relation to the earths surface.
Therefore Geosynchronous satellites are therefore best suited to data gathering applications, such as weather satellites.
Data gathering applications, only need to download data periodically.
This means that not being in continual transmission contact with a groundstation on earth, is not important.
Geostationary satellites effectively rotate with the earth.
This means that they are over the same landmass at all times.
Geostationary satellites are suitable for continuous contact a fixed area of earth.
An example of their use, is for satellite television.
The distance from earth in geostationary orbit is 35790 km.
Medium earth orbit satellites, is often shortened to MEO.
Medium Earth Satellites, are at a distance from the earth, between the high and low range of orbits.
The distance of a MEO satellite from the earth, is between 1200 – 35790 km.
So finally lets look at what are LEO low earth orbit satellites.
Lets remind ourselves that LEO is stands for Low Earth Orbit.
LEO orbits are closest to the earth of the satellite orbits used.
Typically a LEO orbit is between 500 – 1000 miles from the earth.
In kilometres this is 800 – 1600 km.
So lets look at the characteristics of LEO satellites.
As satellites in LEO are closer to the earth, they need less rf transmission power.
Another advantage …tbc