Subelement P: Satellite— Topic 95: Low Earth Orbit Systems
Question 3-95P1
Element 3 (GROL)What is the orbiting altitude of the Iridium satellite communications system?
Explanation
The Iridium satellite communication system operates in Low Earth Orbit (LEO). LEO satellites, as their name suggests, orbit relatively close to the Earth, typically between 100 and 1200 miles altitude. The Iridium constellation specifically orbits at an altitude of approximately 485 miles (780 km).
This lower altitude is chosen to minimize path loss and signal latency, allowing for smaller, less powerful handheld devices. However, because they are so close, LEO satellites move rapidly across the sky, necessitating a large constellation (like Iridium's 66 active satellites) to provide continuous global coverage.
The other options represent different types of orbits:
* 22,184 miles is the approximate altitude for Geostationary Earth Orbit (GEO) satellites, which appear fixed in the sky relative to the ground.
* 11,492 miles and 4,686 miles fall within the range for Medium Earth Orbit (MEO) satellites, used by systems like GPS.
Related Questions
3-94O5 Exposure to microwave energy from RADAR or other electronics devices is limited by U.S. Health Department regulations to _______ mW/centimeter.3-94O6 RADAR collision avoidance systems utilize inputs from each of the following except your ship’s:3-95P2 What frequency band is used by the Iridium system for telephone and messaging?3-95P3 What services are provided by the Iridium system?3-95P4 Which of the following statements about the Iridium system is true?