GEO Satellite Orbit: Advantages and Disadvantages

This article explores the pros and cons of Geostationary Earth Orbit (GEO). It details both the advantages and disadvantages of utilizing GEO for satellite communications.

GEO, which stands for Geosynchronous or Geostationary Earth Orbit, is one of the three primary types of orbits, alongside Low Earth Orbit (LEO) and Medium Earth Orbit (MEO). These orbit types are categorized based on their distance from the Earth, ranging from the closest (LEO) to the farthest (GEO).

Satellites are placed in these orbits after launch to serve various purposes.

Here are some key features of GEO orbit:

• Orbit Period: 24 hours
• Orbit Height from Earth: 35,800 km
• Satellite Life in Orbit: Long
• Propagation Loss: Highest
• Number of Satellites for Global Coverage: 3

Figure 1 depicts GEO (Geosynchronous or Geostationary Earth Orbit).

For a deeper understanding, refer to the differences between geosynchronous and geostationary orbits, as well as resources covering LEO vs. MEO vs. GEO and satellite fundamentals.

Advantages of GEO (Geosynchronous Earth Orbit)

Here are the advantages of using a GEO orbit:

• Wide Coverage Area: Its high altitude allows it to cover a large geographical area. Consequently, only three satellites are needed to provide coverage for the entire Earth.
• Continuous Visibility: Satellites remain visible 24 hours a day from a fixed location on Earth.
• Ideal for Broadcasting: Well-suited for broadcasting and multi-point distribution applications.
• Simplified Ground Station Tracking: Ground stations do not need to track the satellite, as it remains continuously visible from a fixed location.
• No Inter-Satellite Handoff: No need for seamless transitions between satellites.
• Fewer Satellites Required: Only three satellites are sufficient to cover the entire Earth.
• Minimal Doppler Shift: Reduces complexity in receiver design for satellite communication, as there is almost no doppler shift

Disadvantages of GEO (Geostationary Earth Orbit)

Here are the drawbacks of using a GEO orbit:

• Significant Signal Delay: The signal requires a considerable amount of time to travel from Earth to the satellite and back. The round-trip delay is approximately 240ms (120ms in each direction). This latency due to the 35,786 km distance and signal speed of 3x10^8 m/sec.
• Not Suitable for Time-Critical Applications: The delay makes it unsuitable for point-to-point applications that require real-time interaction, such as voice and video conferencing.
• Poor Coverage at Polar Regions: Located above the equator, GEO struggles to broadcast effectively near the polar regions.
• Weak Signal Strength: The long transmission distance results in a weak received signal.
• Higher Equipment Costs: Ground stations require better Low Noise Amplifiers (LNAs) and advanced signal processing, increasing equipment costs.
• Limited Coverage at High Latitudes: Provides poor coverage at latitudes typically greater than 77 degrees.