Space Communication-Modulation of Space communication

Space Communication-Modulation of Space communication

As we know about the bandwidth of the frequency, Bandwidth of the Transmission medium. But we are Discuss about the “Space Communication-Modulation of Space communication”. And some types of the modulation of the Space communication.


Space Communication-Modulation of Space communication

The communication process in which free space used as a transmission medium is called Space Communication. Radio, TV and satellite communication are the example of space communication. All these types of communication makes the use of Radio waves.

The electromagnetic waves of frequency ranging from a few kilo hertz to a few hundred mega hertz are called radio waves.

Depending upon the modulation process, space communication has following two types:

  1. Amplituded Modulated Communication
  2. Frequency Modulated Communication


An amplitude Modulated signal can be transmitted from the antenna by the following two possible ways:

a) Ground / Surface wave Propagation: when amplitude modulated radio waves can travel directly from one point to another point on the surface of earth. It is known as ground wave surface wave propagation.

This type of propagation is used for only low and medium frequency i.e up to 1500 kHz (or wavelength more than 200 m). That is why; it is also known as medium wave propagation and generally used for local broadcasting. For TV and FM signals the ground wave propagation is not used.

NOTE: For TV and FM signals of very high frequencies are required.

b) Sky wave Propagation: when the radio waves from the transmitting antenna reach the receiving station after reflection from the receiving station after reflection from ionosphere, the wave propagation is called sky-wave propagation. The electromagnetic waves of frequencies more than 1500 kHz up to 40 MHz (or wavelength less than 7.5 m – 200 mm) sky wave propagation is used. The em waves of frequency greater than 40 MHz cannot reflected by the ionosphere. For such frequencies satellite communication is used.


When the frequency of the propagation of the wave becomes greater than 40 MHz, then propagation is not possible with ground wave propagation or sky wave propagation. for the propagation of such frequencies space wave propagation is used.

For Example: TV signals cannot be transmitted via sky wave propagation as ionosphere cannot reflect back such high frequencies. In such case, Satellite communication is used.

These are modules of space communication. any you have any Question and query about the “Space Communication-Modulation of Space communication”. Feel free to comment on down below.

Be the first to comment

Leave a Reply

Your email address will not be published.


This site uses Akismet to reduce spam. Learn how your comment data is processed.