Q 2.3 How do communication satellites work?
Communication satellites receive signals from ground transmitters, commonly known as Earth stations. Since the received signals are very weak these…
Q 2.4 Which orbits are used for satellite communications?
A majority of communication satellites are located in a geostationary orbit wherein satellites appear stationary from the Earth. At an…
Q 2.5 Give an overview of satellite design.
In broad terms communication satellites comprise a platform or ‘bus’ and payload. The bus assists in maintaining satellite attitude and…
Q 2.6 Which services are suitable for geostationary satellites?
Satellite communication is economic when separation between users is large (hundreds of kilometre), in presence of difficult terrain or sea…
Q 2.7 What are the advantages of geostationary orbit?
Participating ground stations do not require elaborate tracking as required by other types of orbits. Radio links and interference environment…
Q 2.8 What are the disadvantages of geostationary orbit?
Due to large distance of geostationary satellites from the Earth, the free space loss and propagation delay is significant. Satellites…
Q 2.9 What are the advantages of low and medium Earth orbit satellite constellations for telecommunications services?
Low and medium Earth satellite exhibit lower propagation delay resembling terrestrial systems. These orbits can provide full global coverage. Power…
Q 2.10 What are the disadvantages of low and medium Earth orbit for telecommunication services?
Low and medium Earth orbit require a large number of satellites for global coverage. Due to their high motion, received…
Q 2.11 How are satellites launched?
Geostationary satellites can be launched directly into orbit. However, it is usual to launch them in a sequence outlined below….
Q 2.12 Can satellites track mobile phones?
Satellites are not used for tracking any particular mobile phone. Mobile phones estimate their own position from signals transmitted by…