Q16) What is Geostationary Satellite ?
Answer: A geosynchronous satellite is a satellite in geosynchronous orbit, with an orbital period the same as the Earth's rotation period. Geosynchronous satellites have the advantage of remaining permanently in the same area of the sky, as viewed from a particular location on Earth, and so permanently within view of a given ground station.
Geostationary satellites have the special property of remaining permanently fixed in exactly the same position in the sky, as viewed from any location on Earth, meaning that ground-based antennas do not need to track them but can remain fixed in one direction. Such satellites are often used for communication purposes; a geosynchronous network is a communication network based on communication with or through geosynchronous satellites.
Q17) What is the radius of Earth ?
Answer: Radius of Earth: 6,378Km
Q18) What is Satellite Period ?
Answer: The period of satellite is the time it takes to make one full orbit around an object [ie. an Earth].
Q19) What is the height of geostationary satellite orbit from surface of earth ?
Answer: The height of geostationary satellite orbit from surface of earth: 35,786Km.
Q20) What is the height of geostationary satellite orbit from center of earth ?
Answer: The height of geostationary satellite orbit from center of earth: 42,164Km.
- "Radius of Earth + Geostationary satellite orbit from surface of earth"
Q21) What are types of orbit ?
Answer:
- Geostationary orbit (GEO)
- Low Earth orbit (LEO)
- Medium Earth orbit (MEO)
- Polar orbit and Sun-synchronous orbit (SSO)
- Transfer orbits and geostationary transfer orbit (GTO)
Q22) What are the different types of satellites in use today ?
Answer: he satellites are categorized into active satellite and passive satellite. Further satellite types include Geostationary satellite, LEO satellite and MEO satellite.
Q23) What are geostationary satellites?
Answer:
- Geostationary satellites are those :
- The satellites present in the geostationary orbit are called geostationary satellite.
- The geostationary orbit is one in which the satellite appears stationary relative to the earth.
- It lies in equatorial plane and inclination is ‘0’.
- The satellite must orbit the earth in the same direction as the earth spin. The orbit is circular.
Q24) How many Geosynchronous satellite is needed to cover the whole earth ?
Answer: 3 Satellites needed
Q25) What are the types of satellite launch vehicle ?
Answer:
- Launch Vehicles are used to carry spacecraft to space.
- Augmented Satellite Launch Vehicle(ASLV)
- Polar Satellite Launch Vehicle(PSLV)
- Geostationary Satellite Launch Vehicle(GSLV)
Satellite Launch Vehicle types are:
Q26) Difference between FDM and FDMA.
Answer: They are analogous to each other but multiplexing is transmission feature and multiple access is traffic feature.
Q27) What is the function of preamble and guard time in TDMA ?
Answer:
- TDMA stands for Time Division Multiple Access.
- Preamble: Certain time slots at the beginning of each burst are used to carry timing and synchronizing information. These time slots collectively are referred as Preamble.
- Guard time is necessary to prevent the two bursts from overlapping and it varies from burst to burst.
Q28) What are the limitations of FDMA in satellite ?
Answer:
- FDMA stands for Freqency Division Multiple Access
- TDMA stands for Time Division Multiple Access
LIMITATIONS are: - lf the traffic in the downlink is much heavier than that in the uplink, then FDMA is relatively inefficient.
- Compared with TDMA, FDMA has less flexibility in reassigning channels.
- Carrier frequency assignments are hardware controlled.
Q29) What is VSAT ?
Answer: VSAT stands for very small aperture terminal which is used for long distance low density voice and data communications.
Q30) What is MSAT ?
Answer: The mobile satellite network popularly known as MSAT used to provide cellular communication via satellite.
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