Satellite Transmission: Overview and History

Satellite Transmission

There are around 2000 man-made asteroids or satellites orbiting the Earth. They carry information, video and voice through Cognet or analogue and binary or digital signals from one place to another on the Earth.

The use of artificial satellites to facilitate with communication links between different points of the globe is known as Satellite communication. It plays a crucial role in the worldwide telecom system.

Satcom works through two different mechanisms, the first one is the ground segment. Ground segment consists of static mobile communication, receiver and additional equipment. The second one is the space segment that primitively includes the man-made satellite. The satellite link includes the up-linking of a signal that is emitted from an earth station towards a satellite. It receives the signal and exaggerates the same. Then, it retransmits the signal to Earth. The earth station gets it and re-exaggerates the signal. The example of ground receivers is DTH system, mobiles, aircraft signalling apparatus and telephones.

satellite communication system

Now, let’s check out how it works.

A communication satellite is just a microwave repeater station in space. A repeater is actually a circuit that increases the signal strength and retransmits the same. It works as a transponder that modifies the frequency band of the transmitted signal from the received ones. A frequency through which the signal is sent to space from the earth station is known as uplink and the reverse signal from the satellite is called downlink. To understand this better, please go through the following figure.

History of Satcom

The concept of communicating using the satellites was first noticed in the story “The Brick Moon”. This story construes the making and launch of a satellite in Earth’s orbit. The diameter of the asteroids was 60 meters and it was constructed with bricks.

The first applied idea of satcom was planned by Arther C Clarke, an officer of the British Air Force. He told that if a satellite can be launched at 35,786 Km of altitude can move at the similar speed of Earth’s rotation. At this altitude, it would be static in a position relating to a particular point of Earth. This orbit, better known as geostationary orbit these days, is great for satcom. It would simply require a grounded antenna pointed to the satellite for a 24*7 coverage. In his study, Clarke calculated that three satellite spaced in an equal distance from one another in geostationary orbit could support worldwide coverage.

The first-ever artificial satellite was launched by the Soviet Union on 4th of October, 1957. It was named as ‘Sputnik 1’. It used to transmit for 22 days. This was because of its battery life. Its launch geared the space race among several countries of the World.

This was an overview of the current satellite communication system and the history of the same. Hope you find this article useful.