What is a Satellite?
This satellite tutorial covers what is a satellite,include both natural satellite and artificial communication satellite. It covers function of satellite transponder.
The object orbiting the other big object in the space is called satellite for example the Earth moves around the Sun, hence here Earth is the satellite, often called as natural satellite.
There are man-made satellites usually launched into the space for specific purpose. The purpose can be to take pictures/photos of the other planets and also of earth. This help scientists understand and do research on universe and also on solar system. The first artificial satellite was Sputnik 1 launched by Soviet Union.
The main functions of this artificial satellite launched by human beings are many as mentioned below:
• To take pictures of the object under study and send it to the earth for analysis.
• TV signal broadcasting
• Voice calls via satellite in the terrain and hilly regions of the earth, Iridium project was pioneer for this concept of providing satellite phone communication using constellation of about 66 active satellites in the orbit around the Earth.
• Weather and climate related information
• Helps in irrigation by finding fertile lands and other land exploration details useful for farmers
The function of this communication satellite is to receive signal from earth and transmit the same signal to broad area of the earth. Satellite does frequency conversion and amplification of the received signal before relaying back the signal to the earth. Satellite transponder does this operation. The same is explained below with the use of the block diagram.
About satellite transponder
As shown in the figure, satellite transponder receives signal of say 6175 MHz from the earth, it converts the same to 3950 MHz by substracting it using LO of 2225 MHz. This is for C band satellite band. It does amplification of the signal in addition to the frequency translation. Typically there will be about 12 or 24 transponders available in the satellite.
To know more about satellite go through following mentioned links:
Satellite tutorial what is a satellite Satellite frequency bands of operation Parts of a satellite Satellite Orbits Satellite Services Satellite types Satellite Capacity Allocation Satellite Network Configuration Satellite Applications Satellite Terminology Satellite Applications Satellite Launch Procedure Remote sensing satellites Satellite TTC Satellite Launch Service Providers Satellite Parts Manufacturers