TopBand: 160 M and Greyline Chart
KE1YRolf@aol.com
KE1YRolf@aol.com
Sat, 13 Jun 1998 08:14:50 EDT
Hi friends,
I just spoke to a friend and he relayed the following message:
Look up ==>> <A HREF="http://holly.cc.uleth.ca/solar/www/topband.html">
http://holly.cc.uleth.ca/solar/www/topband.html</A>
and you will see the greyline pattern, being udated every 5 min. IT WORKED !!
They also have other very informative low band DXing stuff made available to
users. You can also subscribe and get daily information for free.
Here is more info, displayed right under their "real time" clock and panorama.
========= cut and pasted========
The map above can be used by Topband operators to determine the current
location of the grayline (sunrise/sunset terminator), and other useful
information regarding the state of the Earth's ionosphere and auroral zones.
The sunrise/sunset terminator is the thick solid gray line that is located
nearest the Sun symbol (the symbol showing where the Sun is positioned
directly overhead). The other thick gray line represents regions where the Sun
has set on the ionosphere.
The green lines show the locations of the auroral ovals. Topband radio
communicators should interpret these green lines as follows: The regions
between the green lines show areas where auroral activity is most likely to be
observed. They do NOT necessarily represent the location or current
latitudinal thickness of the auroral ovals! But the auroral oval should be
located somewhere between the green lines. For the precise location of the
auroral oval, consult the previous ultraviolet aurora maps shown above.
For convenience only, the great-circle path from the eastern U.S. to Japan is
shown on the plot, with the distance between these two points displayed at the
mid-point of the path, in kilometers.
The cyan-colored contours represent the estimated maximum usable frequencies
for paths of 3,000 kilometers. Consult the Realtime MUF Map section for more
details regarding the use of these contours.
Have fun, I never saw their page before, it might have been a well kept
secret.
73
Rolf, KE1Y
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