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Hi Markus, I may have has my tongue in my cheek
about the "big beach" called the Sahara
:-))
I noticed difficult to understand variations on the
signal from Marathon in 2002, which crosses the Alps on its way to the UK. I
suspended trying to use Marathon as a beacon, though Brian in Porto got much
more sensible data on a mainly water path.
There was some geomagnetic activity activity early
this morning (0300 to 0900) TheDst has dropped to -130nT by 12:00 but any effect
may take some time to diffuse to equatorial path and the precipitation may
disperse before it has too significant an impact on signals there. Thepredition
for the CME was later today. I am not sure whether it arrived sooner than
expected or whether we will get a double hit. Although it was not Earth directed
it seemed to sweep up plasma from a significant Coronal Hole flow and this
looked, from the NOAA SEC animation, to enhance the effect to Earth even though
it was not a "direct hit"
Tonights results could be very interesting.....we
have never had a trans equatorial path to investigate before.
Alan
G3NYK
----- Original Message -----
Sent: Saturday, November 07, 2015 11:01
AM
Subject: Re: LF: Re: FR5ZX WSPR
again
Here's another plot for FR5ZX decodes
showing Thursday / Friday night. Nice to see even more stations making it to
La Reunion!
Generally I would agree with Alan that low-angle
ground reflections from a planar dielectric surface (sand) may be nearly
as effective as from a conductor (salt water), and that on the other hand
scattering off mountain ranges may significantly hinder or interrupt
long-range propagation. However the Sahara is not really all
flat...
Yesterday night propagation appeared to be weaker
and short-lived - only 18 spots alltogether and the last one at 22:46 UT.
Coronal mass ejection arrived on earth?
All the best,
Markus
Sent: Friday, November 06, 2015 1:54 AM
Subject: Re: LF: Re: FR5ZX WSPR again
Hi Stefan yes it's interesting because there has
be steady low level
geomagnetic storms since the 3rd at Kp=5. I am
wondering if what we are
seeing is more a feature of a predominantly
N<>S path rather than the more
usual long, predominantly E<>W
paths to Joe and Alex. I suppose crossing the
Equator there is much less
effect from precipitated electrons which happens
mainly at, or near, the
poles.
An interesting way of analysing the 9000km path would be to cut
it into 4
hops and see where the ground interaction takes place. (it is
roughly 2000
to 2500km per hop) I do wonder if the desert (quartz) might
have a similar
effect to sea. (the desert sand was given as one reason why
the "Poynting
vector" aerials seemed to give good results in
Egypt)
The signal doesnt really "bounce" if you draw the profile
accurately it
approached the ground at near zero degrees. I have a feeling
that the long
distance signal may be more affected by the ground
"roughness"
(scattering??) at mid-path than the resistivity/permiability.
In fact most
of the signal just skims the ground. There is no doubt the
sea effect is
certainly clear at the path ends. There was some
suggestion of preferential
N<>S paths between ZL and Asia, but
strangely it was never as good to
W.Coast/Alaska or
Honalulu.
What is surprising is that there are not similar paths to
South America from
Europe. However the question is then " is anyone
monitoring". Likewise to
RSA but I believe LF is not popular with amateurs
in ZS.
It will be interesting to see what happens when the CME arrives
overnight on
the 7th. It may not affect the path to La Reunion until the
night of 7/8.
I noticed a set of regular 4min interval decodes then a
16 min blank which I
presume must have been a fade. Also your best
reception was soon after the
fade I think??
Fascinating stuff this
LF/MF propagation :-))
Alan
G3NYK
----- Original
Message -----
From: "DK7FC" <[email protected]>
To:
<[email protected]>
Sent:
Thursday, November 05, 2015 11:54 PM
Subject: Re: LF: Re: FR5ZX WSPR
again
> Attached is a picture showing the path for EA5DOM. So
far i thought that
> the red sea is supporting the path for stations
from DL, PA, SV and I,
> allowing one or 2 hops on sea water. But now
Luis' path is directly over
> Africa.
> Hmmmm, Alan? Any thoughts?
:-)
>
> 73, Stefan
>
> Am 05.11.2015 23:59, schrieb
VIGILANT Luis Fernández:
>> Wops
!!
>>
>> 2015-11-05 22:48 EA5DOM 0.475790 -20 0
IM98wn 0.05 FR5ZX LG78pu 8796
>>
>> New coil ! Antenna is
finally on resonance ..... and seems to work !
;-)
>>
>> 73 de Luis
>> EA5DOM
>
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