[TowerTalk] fading and the value of 1 dB

[Lux, Jim]

Here's some references that are interesting...

https://www.isode.com/whitepapers/skywave.html  talks about variations 
over 10 seconds to a few minutes.

http://tracebase.nmsu.edu/hf/reports/walnut.pdf describes a model of HF 
links.

And gives some statistics. D (decile value of variability) = 1.28*SigmaN 
(SigmaN = SD of noise power)

3 MHz D is about 8 dB during stable hours and ranges from 10-17 during 
transition

10MHz D is 5 dB during stable hours, 7-11 transition.



Shorter term variations (Rayleigh fading) - those are modeled by what's 
called the Watterson model.