[TowerTalk] EMI and lightning flash rate data?

[jimlux]

This is more HF radio  related than specifically towers, but it does 
relate to "station planning".

I've been working with some very sophisticated HF propagation modeling 
tools (PHARLAP - it's a detailed ray tracing code that is much more 
detailed than VOACAP).  I'm trying to build a model of received noise, 
and what I'd like to do is model the atmospheric noise, as propagated to 
a receiver site.

What I'm looking for, ideally, is gridded atmospheric RF noise vs time 
of day and day of year (climatology).  Since the dominant source of that 
noise is likely lightning, a gridded climatological database of 
lightning flash rates would probably work.

The other thing that would be useful is some gridded database for human 
generated noise. I've been thinking about using something like the 
"earth at night" image and using the illumination density as a proxy for 
urban vs rural.


Ultimately, the idea is to figure out what elevation angle pattern would 
optimize the SNR for DX - if your desired DX is in the middle of a 
thunderstorm, nothing's going to help.  But if the noise is coming from 
somewhere else, then maybe you can put a null on it.  Stacked Yagis are 
the traditional approach here (top/bottom/BIP/BOP with a switch box), 
but a variable phase shifter might be more powerful than a switch box.