MEO Satellite Knowledge Test

1. What is the approximate altitude range of MEO satellites?

a) 160-2,000 km
b) 2,000-35,786 km
c) 35,786-50,000 km
d) Above 50,000 km

The correct answer is b) 2,000-35,786 km. MEO satellites operate between Low Earth Orbit (LEO) and Geostationary Orbit (GEO). This altitude provides a balance between coverage area and signal delay, making it ideal for navigation systems.

2. Which of the following satellite systems primarily uses MEO?

a) Iridium
b) GPS
c) Intelsat
d) Hubble Space Telescope

The correct answer is b) GPS. The Global Positioning System operates in MEO at about 20,200 km altitude. Iridium is LEO, Intelsat is GEO, and Hubble is in LEO.

3. What is the approximate orbital period of a typical MEO satellite?

a) 90-120 minutes
b) 2-24 hours
c) Exactly 24 hours
d) 7-10 days

The correct answer is b) 2-24 hours. MEO satellites have orbital periods between LEO (90-120 min) and GEO (24 hours). GPS satellites have a period of about 12 hours.

4. Compared to LEO satellites, MEO satellites have:

a) Smaller coverage area but lower latency
b) Larger coverage area but higher latency
c) Similar coverage and latency
d) No coverage area advantage

The correct answer is b) Larger coverage area but higher latency. MEO satellites cover more area than LEO but have slightly higher signal delay (though much less than GEO).

5. What is the main advantage of MEO for navigation systems like GPS?

a) Lowest possible latency
b) Best possible resolution for Earth imaging
c) Optimal balance between coverage and signal delay
d) Stationary position relative to ground

The correct answer is c) Optimal balance between coverage and signal delay. MEO provides wide enough coverage to need fewer satellites than LEO, while maintaining acceptable signal delay for navigation purposes.

6. How many operational GPS satellites are typically in the constellation?

a) 6-12
b) 24-32
c) 50-100
d) More than 200

The correct answer is b) 24-32. The GPS constellation maintains 24 operational satellites (plus spares) in six orbital planes to ensure global coverage.

7. What is the primary reason MEO isn't used for Earth imaging satellites?

a) Too much atmospheric interference
b) Resolution limitations due to altitude
c) Inability to maintain stable orbit
d) Excessive power requirements

The correct answer is b) Resolution limitations due to altitude. The higher altitude of MEO makes it difficult to achieve the high resolution needed for most Earth imaging applications, which typically use LEO.

8. Which of these is NOT a challenge specific to MEO satellites?

a) Higher radiation exposure than LEO
b) More complex ground station tracking than GEO
c) Rapid orbital decay
d) Longer signal delay than LEO

The correct answer is c) Rapid orbital decay. Unlike LEO, MEO satellites experience minimal atmospheric drag and thus don't have rapid orbital decay. The other options are genuine MEO challenges.

9. The GPS constellation uses how many orbital planes?

a) 1 (equatorial)
b) 3
c) 6
d) 12

The correct answer is c) 6. GPS satellites are arranged in six orbital planes (55° inclination) with 4-5 satellites each, ensuring at least 4 satellites are visible from anywhere on Earth.

10. What frequency bands are typically used by MEO navigation satellites?

a) L-band (1-2 GHz)
b) C-band (4-8 GHz)
c) Ku-band (12-18 GHz)
d) Ka-band (26-40 GHz)

The correct answer is a) L-band (1-2 GHz). GPS and other navigation systems use L-band because it offers good penetration through the atmosphere and reasonable antenna sizes for handheld devices.

Medium Earth Orbit (MEO) Satellite Knowledge Test