Oblique Azimuthal Equidistant Map Projection
This map is a special map projection that displays great-circle paths as
straight lines. Each of the azimuthal lines (or "spokes") radiating from the
center of the map and labelled on the outside of the map are great-circle paths
from the location where the azimuthal lines converge to every other region of
the world. Each line represents a great-circle path along the given azimuth.
For example, the line pointing straight up toward the top of your screen is the
great-circle path for signals directed at an azimuth of zero degrees
The white dots labelled on this map represent the magnetic observatories that
were used to form the prediction table. They are also the same magnetic
observatories for which current geomagnetic data is displayed.
Use this map, together with the aurora images and the geomagnetic K-index data
to determine whether or not your signal path crosses into an area of more
active auroral or geomagnetic activity. If it does, your chances of observing
DX are reduced.
This map can be used to form predictions for other areas of the world that pass
through the auroral zones. To do this, look at the proximity of your signal
path (the appropriate azimuth line) to one or more of the magnetic
observatories (white dots). For each station that your signal closely
approaches, check the geomagnetic K-index data. If K-indices of 3 or more are
observed anytime over the last 7 hours, you may experience difficulties
establishing contact with the destination on 160 meters. If K-indices are
consistently less than 3 (preferably a stable 0 or 1), your chances of making
contact will be much better.
It is important to remember that propagation on 160 meters often does
not follow the great-circle path, so use these maps as a general guide,
not a definitive plot of exactly where your signal will go.
These maps were produced using our PROPLAB-PRO HF Radio
Propagation Laboratory Software.