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  • Topic: Satellite, Communications satellite, Geosynchronous orbit
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Satellite Communications
Reference book:
Satellite Communications, 3rd ed.
Dennis Roddy
McGraw-Hill International Ed.

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1.1 Introduction
Features offered by satellite communications
‡ large areas of the earth are visible from the satellite, thus the satellite can form the star point of a communications net linking together many users simultaneously, users who may be widely
separated geographically
‡Provide communications links to remote communities
‡Remote sensing detection of pollution, weather conditions, search and rescue operations.

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1.2 Frequency allocations
‡ International Telecommunication Union
(ITU) coordination and planning
‡ World divided into three regions:
± Region 1: Europe, Africa, formerly Soviet
Union, Mongolia
± Region 2: North and South America,
Greenland
± Region 3: Asia (excluding region 1), Australia,
south west Pacific

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‡ Within regions, frequency bands are allocated to various
satellite services:
‡Fixed satellite service (FSS)
‡Telephone networks, television signals to cable

‡Broadcasting satellite service (BSS)
‡Direct broadcast to home Astro is a subscription-based
direct broadcast satellite (DBS) or direct-to-home satellite television and radio service in Malaysia and Brunei

‡Mobile satellite service
‡Land mobile, maritime mobile, aeronautical mobile

‡Navigational satellite service
‡Global positioning system

‡Meteorological satellite service
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Frequency band designations in common use for
satellite service

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1.3 Intelsat
‡ International Telecommunications Satellite
‡Created in 1964, now has 140 member countries, >40
investing entities
‡Geostationary orbit

orbits earth`s equitorial plane.

‡Atlantic ocean Region (AOR), Indian Ocean Region
(IOR), Pacific Ocean Region.
‡Latest INTELSAT IX satellites wider range of service
such as internet, Direct to home TV, telemedicine, teleeducation, interactive video and multimedia

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Satellite Coverage Maps

Source: http://www.intelsat.com
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Coverage maps: Footprints

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1.4 U.S DOMSAT (Domestic Satellites)
‡Provide various telecommunication service within a
country
‡In U.S.A all domsats in geostationary orbit
‡Direct-to-home TV service can be classified as high
power, medium power, low power

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1.5 Polar orbiting satellites
‡ Orbit the earth such a way as to cover the north and
south polar regions
‡ A satellite in a polar orbit passes above or nearly above both poles of the planet (or other celestial body) on each
revolution. It therefore has an inclination of (or very close to) 90 degrees to the equator.
‡ Since the satellite has a fixed orbital plane perpendicular to the planet's rotation, it will pass over a region with a
different longitude on each of its orbits.
‡ Polar orbits are often used for earth-mapping-, earth
observation- and reconnaissance satellites, as well as
some weather satellites.

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The orbit of a near polar
satellite as viewed from a
point rotating with the Earth.

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‡ in U.S.A, the National Oceanic and Atmospheric
Administration (NOAA) operates a weather satellite system,
geostationary operational environmental satellites
(GEOS) and
polar operational environmental satellites (PEOS)

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2.0 Orbits and Launching Methods
‡ Johannes Kepler (1571 ±1630) derive empirically three
laws describing planetary motion.
‡ Kepler¶s laws apply quite generally to any two bodies in space which interact through gravitation.
‡ The more massive of the two...
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