Low Earth Orbit (LEO) vs Geostationary (GSO)
When it comes to satellite constellations, two types come to mind: Low Earth Orbit (LEO) and Geostationary (GSO). Both constellations have their advantages and disadvantages. In this post, we will compare the two and see how they stack up against each other.
What is a Low Earth Orbit (LEO) Satellite Constellation?
A Low Earth Orbit (LEO) satellite constellation consists of multiple satellites orbiting the Earth at an altitude of 2,000 kilometers or less. LEO satellites are relatively close to the Earth's surface and are used for a variety of purposes, such as communications, imaging, and scientific research.
LEO satellites are known for their low latency and high data transfer rates. Because they are closer to the Earth's surface, they require less power to transmit data and have a shorter signal path than GSO satellites.
What is a Geostationary (GSO) Satellite Constellation?
A Geostationary (GSO) satellite constellation consists of one or more satellites orbiting the Earth at an altitude of 35,786 kilometers or more. GSO satellites orbit at the same speed as the Earth's rotation, which allows them to remain stationary relative to a specific point on the Earth's surface.
GSO satellites are often used for telecommunications and broadcasting purposes because of their wide coverage area. However, because they are further away from the Earth's surface, they have a longer signal path and require more power to transmit data than LEO satellites.
Comparison
Now that we know the basics of LEO and GSO satellite constellations let's compare the two:
Latency: LEO satellites have low latency because they are closer to the Earth's surface. GSO satellites have a higher latency because they are further away from the Earth's surface.
Coverage: GSO satellites have wider coverage areas because of their distance from the Earth's surface. LEO satellites, on the other hand, require a constellation of multiple satellites to achieve full coverage.
Signal Path: LEO satellites have a shorter signal path than GSO satellites due to their proximity to the Earth's surface.
Power Requirements: GSO satellites require more power to transmit data than LEO satellites.
Costs: GSO satellites are generally more expensive to build and launch than LEO satellites.
Which One Should You Choose?
The choice between LEO and GSO satellites depends on the specific requirements of the mission. If you need low latency and high data rate, then LEO satellites are the way to go. If you need wide coverage and don't mind higher latency, then GSO satellites are the better choice.
There are also hybrid constellations that incorporate both LEO and GSO satellites to take advantage of the strengths of both types.
References
[1] https://www.nasa.gov/centers/goddard/about/people/RSchultz_GT.html
[2] https://www.satsig.net/orbit-types/low-earth-orbit.htm
[3] https://www.satsig.net/orbit-types/geostationary.htm