What is satellite communication and how does it function?

Satellite communication is a method of sending and receiving information wirelessly over long distances using artificial satellites orbiting the Earth. These satellites are equipped with specialized radio equipment that enables them to receive, process, and transmit signals to ground stations and other satellites.

Here's how satellite communication functions:

1. The sender of a message, such as a phone call or an email, uses a device like a satellite phone or a computer to transmit the message to a ground station.
2. The ground station receives the message and sends it to a satellite in orbit around the Earth.
3. The satellite receives the message and retransmits it back to Earth, using a different frequency or wavelength to avoid interference.
4. The signal is received by a ground station, which then relays it to the intended recipient, either another ground station or directly to a satellite device.
5. The message is received by the recipient, who can then respond in the same way.

Two different kinds of man-made satellites are used in satellite communication to transmit the signals:

Passive Satellites: Theoretically, an orbiting metallic-coated hydrogen balloon can function as a passive satellite. Such a balloon can reflect microwave signals from one place to another. In orbit, similar inactive satellites can be discovered. These satellites just reflect the signal back towards the Earth; they do not magnify it. Due to environmental attenuation, the received signal is frequently relatively weak because the satellite orbit height can range from 2000 to 35786 km.

Active satellites: Active satellites, in contrast to passive satellites, amplify the sent signals before retransmitting them to Earth, resulting in great signal strength.

The first communication satellites were passive, but today practically all of the new ones are active.Each user is given a separate frequency for transmission to prevent signal mingling and interference.

Use cases of Satellite Communication

Satellite communication plays an important role in our daily life. Following are the applications of satellite communication −

• Radio broadcasting and voice communications
• TV broadcasting such as Direct To Home (DTH)
• Internet applications such as providing Internet connection for data transfer, GPS applications, Internet surfing, etc.
• Military applications and navigations
• Remote sensing applications
• Weather condition monitoring & Forecasting.