02-11-2012, 02:22 PM
Satellite Communication
[attachment=37906]
ABSTRACT
The transfer of information from source to destination i.e transmitter to receiver is called the communication. Basically communication is possible in two ways they are wire communication and the other one is wireless communication. The satellite communication is a best example for the wire less communication. In this paper we are first giving a brief satellite history and next why we are using satellite for communication and the orbital model. How the satellites stay in orbits and orbit types. After we are concentrating how an artificial satellite is launched. And what components required for satellite designers. And after we are giving few applications and key research challenges.
Introduction:
In 1945 Arthur C Clarke suggested that artificial satellites could be employed for communications. In 1957 the Soviet Union successfully launched Sputnik. Since then thousands of satellites have been built and are now used for numerous applications including surveillance, mobile communications, navigation, broadcasting, point to point communications, disaster monitoring, space science, exploration of other planets and earth observation.
Brief Satellite History:
• The world's first manmade artificial satellite (into low earth orbit) was the launch of Sputnik 1, by the USSR (Soviet Union), on October 4, 1957.
• In 1954, the U.S. Navy transmitted voice messages (on microwave carriers) to the moon then detected their reflection back on earth.
• The first broadcast from space to earth was on December 19, 1958, by U.S. president Eisenhower - it was a Christmas greeting - using the SCORE technology.
• A very important and practical development, in the history of satellite communications, was the NASA launch of Tiros I, the world's first weather satellite, launched in April, 1960. It Proved communications via satellite is important for business but using satellites for earth monitoring is important for life - and this is the dual pattern in satellite applications that has been maintained to date. The earth monitoring satellites assist us to understand our world, its impact on us and our impact on it.
Why Satellites for Communications
By the end of World War II, the world had had a taste of "global communications." Edward R. Murrow's radio broadcasts from London had electrified American listeners. We had, of course, been able to do transatlantic telephones calls and telegraph via underwater cables for almost 50 years. At exactly this time, however, a new phenomenon was born. The first television programs were being broadcast, but the greater amount of information required to transmit television pictures required that they operate at much higher frequencies than radio stations. For example, the very first commercial radio station (KDKA in Pittsburgh) operated (and still does) at 1020 on the dial. This number stood for 1020 Kilohertz - the frequency at which the station transmitted. Frequency is simply the number of times that an electrical signal "wiggles" in 1 second. Frequency is measured in Hertz. One Hertz means that the signal wiggles 1 time/second. A frequency of 1020 kilohertz means that the electrical signal from that station wiggles 1,020,000 times in one second.
Satellite Transmitter and receiver:
An "uplink" transmitter on earth, using a "dish" antenna pointed toward the satellite, sends a signal to one of the satellite's "transponders." The transponder amplifies that signal and shifts it to another frequency (so as not to interfere with the incoming signal) to be transmitted back to earth. A "downlink" antenna and receiver on earth then captures that signal and sends it on its way.
Conclusion:
Now a days the communication is essential any where. And we are using satellite communication directly or indirectly in many applications if we develop the satellites. And if we are introducing new technology in satellites then there will be a lot of improvement in the communication. Then there will be a possibility of communication in the remote and rural areas. And also the communication is available at cheaper rate. Like the BSNL “one India”
[attachment=37906]
ABSTRACT
The transfer of information from source to destination i.e transmitter to receiver is called the communication. Basically communication is possible in two ways they are wire communication and the other one is wireless communication. The satellite communication is a best example for the wire less communication. In this paper we are first giving a brief satellite history and next why we are using satellite for communication and the orbital model. How the satellites stay in orbits and orbit types. After we are concentrating how an artificial satellite is launched. And what components required for satellite designers. And after we are giving few applications and key research challenges.
Introduction:
In 1945 Arthur C Clarke suggested that artificial satellites could be employed for communications. In 1957 the Soviet Union successfully launched Sputnik. Since then thousands of satellites have been built and are now used for numerous applications including surveillance, mobile communications, navigation, broadcasting, point to point communications, disaster monitoring, space science, exploration of other planets and earth observation.
Brief Satellite History:
• The world's first manmade artificial satellite (into low earth orbit) was the launch of Sputnik 1, by the USSR (Soviet Union), on October 4, 1957.
• In 1954, the U.S. Navy transmitted voice messages (on microwave carriers) to the moon then detected their reflection back on earth.
• The first broadcast from space to earth was on December 19, 1958, by U.S. president Eisenhower - it was a Christmas greeting - using the SCORE technology.
• A very important and practical development, in the history of satellite communications, was the NASA launch of Tiros I, the world's first weather satellite, launched in April, 1960. It Proved communications via satellite is important for business but using satellites for earth monitoring is important for life - and this is the dual pattern in satellite applications that has been maintained to date. The earth monitoring satellites assist us to understand our world, its impact on us and our impact on it.
Why Satellites for Communications
By the end of World War II, the world had had a taste of "global communications." Edward R. Murrow's radio broadcasts from London had electrified American listeners. We had, of course, been able to do transatlantic telephones calls and telegraph via underwater cables for almost 50 years. At exactly this time, however, a new phenomenon was born. The first television programs were being broadcast, but the greater amount of information required to transmit television pictures required that they operate at much higher frequencies than radio stations. For example, the very first commercial radio station (KDKA in Pittsburgh) operated (and still does) at 1020 on the dial. This number stood for 1020 Kilohertz - the frequency at which the station transmitted. Frequency is simply the number of times that an electrical signal "wiggles" in 1 second. Frequency is measured in Hertz. One Hertz means that the signal wiggles 1 time/second. A frequency of 1020 kilohertz means that the electrical signal from that station wiggles 1,020,000 times in one second.
Satellite Transmitter and receiver:
An "uplink" transmitter on earth, using a "dish" antenna pointed toward the satellite, sends a signal to one of the satellite's "transponders." The transponder amplifies that signal and shifts it to another frequency (so as not to interfere with the incoming signal) to be transmitted back to earth. A "downlink" antenna and receiver on earth then captures that signal and sends it on its way.
Conclusion:
Now a days the communication is essential any where. And we are using satellite communication directly or indirectly in many applications if we develop the satellites. And if we are introducing new technology in satellites then there will be a lot of improvement in the communication. Then there will be a possibility of communication in the remote and rural areas. And also the communication is available at cheaper rate. Like the BSNL “one India”