Comparison Between LEO MEO and GEO

Comparison Between LEO, MEO, and GEO

Comparison Between LEO, MEO, and GEO: The basic difference Between LEO, MEO, and GEO is based on the distance from the earth to the satellite. But before the differences between LEO, MEO, and GEO, we discuss some basics about them.

Non-Geostationary Orbit Satellite Systems

Satellites can be categorized depending on their altitude above the earth’s surface, these are

  1. Geostationary Earth Orbit (GEO)
  2. Medium Earth Orbit (MEO)
  3. Low Earth Orbit (LEO)

The GEO satellite altitude is of around 36,000 km, MEO satellites altitude is in the range of 10,000 to 15,000 km. and LEO satellites are confined between 500 to 1500 km. MEO and LEO satellites are referred to as Non-Geostationary Orbit (NGSO) satellites.

Geostationary Earth Orbit (GEO)

GEO is also called geosynchronous (or synchronous) orbits, which have 23 h, 56 min., 4.091s, or 24 hours period of revolution but are inclined with respect to the equator. Orbits that are below a mean altitude of about 35,784 km have periods of revolution shorter than 24 hours and hence are termed as non-GEO.

GEO satellite has the ability to provide coverage of an entire hemisphere at one time. Satellites are designed to last only about 15 years in orbit, because of the practical inability to service a satellite in GEO and replenish consumables (Fuel, battery cells, and degraded and failed components).

Medium Earth Orbit (MEO)

An MEO satellite is in orbit somewhere between 8,000 km and 18,000 km above the earth’s surface.  MEO satellites are similar to LEO satellites in functionality. The MEO satellites are visible for much longer periods of time than LEO satellites, usually between 2 to 8 hours. MEO satellites have a larger coverage area than LEO satellites. 

Low Earth Orbit (LEO)

LEO satellites are much closer to the earth than GEO satellites, ranging from 500 to 1,500 km above the surface. LEO satellites don’t stay in a fixed position relative to the surface and are only visible for 15 to 20 minutes each pass. A network of LEO satellites is necessary for LEO satellites to be useful.

Comparison Between LEO, MEO, and GEO

Distance from earth100 miles to 300 miles6000 miles to 12,000 miles19,000 miles to 25,000 miles
Rotation period1.5 hours5 to 12 hours24 hours
Numbers of satellites required30 to 6010 to 203 to 6
Life time5 years10 to 15 years10 to 15 years
Launching costLow cost for each satelliteModerate cost for each satelliteHigh cost for each satellite
Coverage areaSmall, therefore hundreds of ground stations are required Large area, therefore less number of ground stations are requiredMuch large area, therefore small number of ground stations are required
Line of sight time0.5 hours2 to 4 hours24 hours
Ellipse intervalFrequency day-night cycle. Satellite remains in darkness 30% of timeInfrequent day-night cycle. Satellite remains in darkness 2% of timeInfrequent day-night cycle. Satellite remains in darkness 1-2% of time
Elevation angle variationRapidly varying elevation angleSlowly varying elevation angleNo variation in elevation angle
TrackingSlow speed trackingSlow speed trackingTracking is not required
Travelling speed17,500 mph10,000 mph 6,879 mph
Application Weather forecastingCommunication and navigation purposeTelephony, data/TV distribution,mobile communication, broadcasting

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