[TowerTalk] One way skip explained

[jimlux]

On 9/12/19 9:32 PM, David Gilbert wrote:
> 
> It was due to the time and space varying nature of the density of the 
> atmosphere all along ...
> 
> https://www.sciencedaily.com/releases/2019/09/190912111010.htm
> 
> Just kidding, of course, but it is pretty interesting.
> 

It is interesting, but you can explain one-way skip fairly easily - the 
ionosphere propagates with two modes (O and X, opposite circular 
polarizations) - the skip distance is different for the two, and if 
you're at the edge of the skip zone, you're in that "caustic" (aka 
bright line) where the signal is stronger than a simple distance 
calculation would give you, but only for one polarization.

If it's a multihop path it gets even more complex, because the 
polarization changes sense when reflecting off the Earth's surface, so 
there's some fairly complex combination of the modes.