In light of this question I was very surprised to learn that despite operating on a higher frequency (108 MHz upwards) than the standard FM broadcasting, airband uses amplitude modulation (AM) instead of the much more robust frequency modulation (FM).

While amplitude modulation allows several senders/receivers to use the same channel and prevents jamming by the capture effect of FM, amplitude modulation should allow lightning strikes to disturb reception.

In Review of Measurements of the RF Spectrum of Radiation from Lightning by David M. Le Vine, NASA Technical Memorandum 87788 we see this chart in Figure 5:

enter image description here

I know that the AM broadcast band around $10^3$ kHz is severely disturbed in thunderstorms; airband is near $10^5$ kHz, so the noise should be being damped by a factor of -25dB (~ factor 1:300).

How is radio reception affected in practice?

  • $\begingroup$ Have any of you pilots or air traffic controllers ever noticed noise from thunderstorms on the radio? $\endgroup$
    – rclocher3
    Jul 26 '18 at 18:30
  • $\begingroup$ In my personal experience, lack of good static discharge has had the most effect in communication. $\endgroup$
    – Mike Brass
    Aug 9 '18 at 0:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.