User:Atul hbk/sandbox

This noise is also called static noise and it is the natural source of of disturbance and is caused by lightning discharge in the thunderstorm and other electrical natural disturbances occuring i the nature because it is in the form of pulse and random in nature and it is spread all over the radio spectrum.It is propagated in the same way as that static will be recieved from all the thunderstorm,local and distant places.

Field Strength
Here Field strength is inversely proportional to frequency so the noise will interfere more with the reception of radio signals (i.e signal modulated by frequency modulation technique ) than signal the television signal ( i.e signal modulated by technique amplitude modulation ). Static noise increase with its level at night at both broadcast and recieving end.

Effect Observed
Atmospheric noise becomes low at frequency above 30Mhz.