This document is an assignment submission for an introduction to satellite systems course. It provides an overview of the history and applications of satellite systems. Key events in satellite history include the launch of Sputnik in 1957 and the first geostationary satellite Syncom in 1963. Satellites are used for weather forecasting, navigation, astronomy, satellite phones, television, military purposes, internet access, and radio. There are four main types of satellite orbits: geostationary (GEO), low earth orbit (LEO), medium earth orbit (MEO), and highly elliptical orbit (HEO).

1. Assignment:
Assignment name: introduction to setelite system
Course tittle:History of setelite system
Course code: CSE 318
Submitted to:
pranab Bandhu nath
senior Lecturer, Department of CSE
City university, Dhaka
Submitted by
Md parvez
Id: 184902610
Bsc in cse(day)
Batch :49th
Introduction to Satellite Systems
o A satellite is an artificial object which is placed intentionally into an
orbit of any natural satellite. Satellites are used for many purposes i.e.
weather forecasting, digital transmission, scientific research and
development etc.
o In a communication context, a satellite is a specialized wireless
transmitter/receiver that is launched by a rocket and placed in orbit
around the earth.
o A satellite can be natural, like the moon, or artificial (human made).
So we can say that a satellite is an object that moves in a curved path
around a planet.

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o Satellite can travel around planets or around stars such as our sun. All
the planets are satellites around the sun.
o Satellites which are far away from the surface of the earth can cover a
wide area on the surface of the earth.
o The moon is earth's original, natural satellite, and there are many
man-made (artificial) satellites for example: SPUTNIK, ECHO, and
SYNCOM.
History of Satellite Systems
There is a long history of the development of satellites system from a
communications point of view. Some important events are shown below in a
tabular form:
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Year Description
1945 Arthur C. Clarke publishes an essay titled "Extra Terrestrial Relays"
1957 First satellite, SPUTNIK

3. 1960 First Reflecting communication satellite, ECHO
1963 First Geostationary satellite, SYNCOM
1965 First Commercial geostationary satellite, "Early Bird" (INTEKSAT I): 240 duplex
telephone channels or 1 TV channel, 1.5 year lifetime.
1976 Three MARISAT satellites for maritime communication.
1982 First mobile satellite telephone system, INMARSAT - A
1988 First satellite system for mobile phones and data communication, INMARSAT -C
1993 First digital satellite telephone system
1998 Global satellite systems for small mobile phones.
Applications of satellites system
1. Weather forecasting
2. Navigation
3. Astronomy
4. Satellite phone
5. Satellite television
6. Military satellite
7. Satellite internet
8. Satellite radio.

4. 1. Weather forecasting
Weather forecasting is the prediction of the future of weather. The satellites that are
used to predict the future of weather are called weather satellites. Weather satellites
continuously monitor the climate and weather conditions of earth. They use sensors
called radiometers for measuring the heat energy released from the earth surface.
Weather satellites also predict the most dangerous storms such as hurricanes.
2. Navigation
Generally, navigation refers to determining the geographical location of an object. The
satellites that are used to determine the geographic location of aircrafts, ships, cars,
trains, or any other object are called navigation satellites. GPS (Global Positioning
System) is an example of navigation system. It allows the user to determine their exact
location at anywhere in the world.
3. Astronomy
Astronomy is the study of celestial objects such as stars, planets, galaxies, natural
satellites, comets, etc. The satellites that are used to study or observe the distant stars,
galaxies, planets, etc. are called astronomical satellites. They are mainly used to find
the new stars, planets, and galaxies. Hubble space telescope is an example of
astronomical satellite. It captures the high-resolution images of the distant stars,
galaxies, planets etc.
4. Satellite phone
Satellite phone is a type of mobile phone that uses satellites instead of cell towers for
transmitting the signal or information over long distances.
Mobile phones that use cell towers will work only within the coverage area of a cell
tower. If we go beyond the coverage area of a cell tower or if we reach the remote
areas, it becomes difficult to make a voice call or send text messages with the mobile
phones. Unlike the mobile mobiles, satellite phones have global coverage. Satellites
phones uses geostationary satellites and low earth orbit (LEO) satellites for transmitting
the information.

5. 5. Satellite television
Satellite television or satellite TV is a wireless system that uses communication
satellites to deliver the television programs or television signals to the users or viewers.
TV or television mostly uses geostationary satellites because they look stationary from
the earth. Hence, the signal is easily transmitted. When the television signal is send to
the satellite, it receives the signal, amplifies it, and retransmit it back to the earth. The
first satellite television signal was send from Europe to North America by using the
Telstar satellite.
6. Military satellite
Military satellite is an artificial satellite used by the army for various purposes such as
spying on enemy countries, military communication, and navigation.
Military satellites obtain the secret information from the enemy countries. These
satellites also detect the missiles launched by the other countries in the space.
Military satellites are used by armed forces to communicate with each other. These
satellites also used to determine the exact location of an object.
7. Satellite internet
Satellite internet is a wireless system that uses satellites to deliver the internet signals to
users. High-speed internet is the main advantage of satellite internet. Satellite internet
does not use cable systems, but instead it uses satellites to transmit the information or
signal.
8. Satellite radio
Satellite radio is a wireless transmission service that uses orbiting satellites to deliver
the information or radio signals to the consumers. It is primarily used in the cars. When
the ground station transmit signal to the satellite that is revolving around the earth, the

6. satellite receives the signal, amplifies it, and redirects the signal back to the earth (radio
receivers in the cars).
Types of Satellite Systems
Satellites have been put in space for various purposes and their placement in space
and orbiting shapes have been determined as per their specific requirements.
Four different types of satellites orbits have been identified. These
are:
o GEO (Geostationary Earth Orbit) at about 36,000km above the earth's
surface.
o LEO (Low Earth Orbit) at about 500-1500km above the earth's surface.
o MEO (Medium Earth Orbit) or ICO (Intermediate Circular Orbit) at about
6000-20,000 km above the earth's surface.
o HEO (Highly Elliptical Orbit)

7. 1. GEO (Geostationary Earth Orbit)
o If a satellite should appear in fixed in the sky, it requires a period of 24
hours. Using the equation of distance earth and satellite, r =
(g.r2
/2.r.f)2
)1/3
and the period of 24 hours f = 1/24 h. the resulting
distance is 35,786 km. the orbit must have an inclination of 0 degree.
o Geostationary satellites have a distance of almost 36,000 km to the earth.
Examples are almost all TV and radio broadcast satellites, any weather
satellites and satellites operating as backbones for the telephone network.
2. LEO (Low Earth Orbit)
o As LEOs circulate on a lower orbit, it is obvious that they exhibit a much
shorter period (the typical duration of LEO periods are 95 to 120 minutes).
Additionally, LEO systems try to ensure a high elevation for every spot on
earth to provide a high quality communication link.
o Each LEO satellite will only be visible from the earth for about ten minutes.
o A further classification of LEOs into little LEOs with low bandwidth services
(some 100 bit/s), big LEOs (some 1,000 bit/s) and broadband LEOs with
plans reaching into the Mbits/s range can be found in Comparetto (1997).
o LEO satellites are much closer to earth than GEO satellites, ranging from 500
to 1,500 km above the surface. LEO satellites do not stay in fixed position
relative to the surface, and are only visible for 15 to 20 minutes each pass.
3. MEO (Medium Earth Orbit)
o A MEO satellite situates in orbit somewhere between 6,000 km to 20,000 km
above the earth's surface.
o MEO satellites are similar to LEO satellites in the context of functionality.
o MEO satellites are similar to LEO satellite in functionality.
o Medium earth orbit satellites are visible for much longer periods of time than
LEO satellites usually between 2 to 8 hours.
o MEO satellites have a larger coverage area than Low Earth Orbit satellites.
o MEOs can be positioned somewhere between LEOs and GEOs, both in terms
of their orbit and due to their advantages and disadvantages.

8. 4. HEO (High Earth Orbit)
o The High Earth orbit satellite is the only non-circular orbit of the four types.
o HEO satellite operates with an elliptical orbit, with a maximum altitude
(apogee) similar to GEO, and a minimum altitude (perigee) similar to the
LEO.
o The HEO satellites used for the special applications where coverage of high
latitude locations is required.
Reference
https://www.javatpoint.com/types-of-satellite-
systems
https://www.physics-and-radio-
electronics.com/satellite-
communication/applicationsofsatellites.html#:~:te
xt=The%20satellites%20that%20are%20used%20
to%20determine%20the%20geographic%20locatio
n,at%20anywhere%20in%20the%20world.
https://www.javatpoint.com/history-of-satellite-
systems