Hi,
I'm observing the strength of HGA22 since some years.
At late evening of 2012-07-02 strong thunderstorm activity happened
over E-Germany/Poland/Czech Republic. That's right below the
reflection area, assuming a 1-hop propagation.
See: http://www.df3lp.de/misc/hga22/propagation_path.png
It's well known that lightnings may heat the ionosphere from
below causing disturbances (SIDs). I very often observed
those phenomena called "early/fast events". But what happened
last Monday evening looks record-breaking. I never saw such
chain of ionospheric disturbances.
See: http://www.df3lp.de/misc/hga22/2012-07-02_thunderstorm.png
Yellow is the raw signal at 10 samples/sec. and blue represents
a running median of 100 data points. The comb-like structures
are from the modulation bursts - I'm receiving the "space"
frequency only. As you can see that's all "signal" and not
qrn/qrm or local interference. A control receiver running
~6km apart confirms the observations.
Peter, df3lp
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