Important Short Questions and Answers: Satellite Applications

SATELLITE APPLICATIONS

1. Give the 3 different types of applications with respect to satellite systems.

• The largest international system (Intelsat)

• The domestic satellite system (Dom sat) in U.S.

• U.S. National oceanographic and atmospheric administrations (NOAA)

2. Mention the 3 regions to allocate the frequency for satellite services.

a. Region1: It covers Europe, Africa and Mangolia

b. Region2: It covers North & South Ameriaca and Greenland.

c. Region3: It covers Asia, Australia and South West Pacific.

3. Give the types of satellite services.

a. Fixed satellite service

b. Broadcasting satellite service

c. Mobile satellite service

d. Navigational satellite services

e. Meteorological satellite services

4. What is mean by Dom sat?

Domestic Satellites. These are used for voice, data and video transmissions within the country.

5. What is mean by INTELSAT?

International Telecommunication Satellite.

6. What is mean by SARSAT?

Search and rescue satellite.

7. What are the applications of Radarsat?

a. Shipping and fisheries.

b. Ocean feature mapping

d. Iceberg detection

e. Crop monitoring

8. What is ECEF?

The geocentric equatorial coordinate system is used with the GPS system.It is called as earth centered, earth fixed coordinate system.

9. What is dilution of precision?

Position calculations involve range differences and where the ranges are nearly equal, any error is greatly magnified in the difference. This effect, brought a result of the satellite geometry is known as dilution of precision.

10. What is PDOP?

With the GPS system, dilution of position is taken into account through a factor known as the position dilution of precision.

11. What is DBS?

Satellites are used to provide the broadcast transmissions. It is used to provide direct transmissions into the home. The service provided is known as Direct Broadcast Satellite services.

Example : Audio, TV and internet services.

12. Give the frequency range of US DBS systems with high power satellites.

a. Uplink frequency range is 17.3 GHz to 17.8 GHz

b. Downlink frequency range is 12.2 GHz to 12.7 GHz

13. Give the frequency range of US DBS systems with medium power satellites.

a. Uplink frequency range is 14 GHz to 14.5 GHz

b. Downlink frequency range is 11.7 GHz to 12.2 GHz

14. What is DTH?

DBS television is also known as Direct To Home ( DTH ).

 DTH stands for Direct-To-Home television. DTH is defined as the reception of satellite programmes with a personal dish in an individual home.

 DTH Broadcasting to home TV receivers take place in the ku band(12 GHz). This service is known as Direct To Home service.

15. Write about bit rates for digital television.

It depends format of the picture.

Uncompressed Bit rate = (Number of pixels in a frame) * (Number of pixels per second) * (Number of bits used to encode each pixel)

16. Give the satellite mobile services.

a. DBS – Direct Broadcast satellite

b. VSATS – Very Small Aperture Terminals

c. MSATS – Mobile Satellite Service

d. GPS – Global Positioning Systems

e. Micro Sats

f. Orb Comm – Orbital Communications Corporation

g. Iridium

17. What is GCC and GEC?

GCC - Gateway Control Centers

GEC – Gateway Earth Stations

18. What is INMARSAT?

It is the first global mobile satellite communication system operated at Lband and internationally used by 67 countries for communication between ships and coast so that emergency life saving may be provided. Also it provides modern communication services to maritime, land mobile, aeronautical and other users.

19. List out the regions covered by INMARSAT.

• Atlantic ocean region, east (AOR-E)

• Atlantic ocean region, west (AOR-W)

• Indian ocean region (IOR)\

• Pacific ocean region (POR)

20.What is INSAT?

INSAT – Indian National Satellite System.

INSAT is a Indian National Satellite System for telecommunications, broadcasting, meteorology and search and rescue services. It was commissioned in 1983. INSAT was the largest domestic communication system in the Asia-Pacific region.

20. List out the INSAT series.

• INSAT-1 • INSAT-2 • INSAt-2A

• INSAT-2E • INSAT-3

21.What is GSM?

GSM (Global System for Mobile communications: originally from Groupe Spécial Mobile) is the most popular standard for mobile phones in the world. GSM differs from its predecessors in that both signaling and speech channels are digital, and thus is considered a second generation (2G) mobile phone system. This has also meant that data communication was easy to build into the system.

22.What is GPRS?

General packet radio service (GPRS) is a packet oriented mobile data service available to users of the 2G cellular communication systems global system for mobile communications (GSM), as well as in the 3G systems. In the 2G systems, GPRS provides data rates of 56-114 kbit/s.

23. What is GPS?

In the GPS system, a constellation of 24 satellites circles the earth in near- circular inclined orbits. By receiving signals from at least four of these satellites, the receiver position (latitude, longitude, and altitude) can be determined accurately. In effect, the satellites substitute for the geodetic position markers used in terrestrial surveying. In terrestrial the GPS system uses one-way transmissions, from satellites to users, so that the user does not require a transmitter, only a GPS receiver.