Topband: A few words

[Robert Brown]

Hello Earl,

My remarks were focused on refraction, a more gradual change in
propagation direction.  Scatter and reflection are other means that can
alter propagagtion direction and give larger effects, although less 
frequent in occurrence.

Your large skew with Myanmar could certainly be due to back-scatter from
a ground reflection.  I know of other contacts where that situation could
explain the result but they are few in number.  Back-scatter from a ground
reflection would not count as a skewing of ionospheric origin and thus
not show any "geophysical signature".
  
On the other hand, a large skewing from auroral activity could easily be
traced in origin by examining auroral zone magnetic records.  In that
case, the magnitude of the electron density would be so high as to
approach something like a metallic reflection and the electron density
gradient would be of less importance.  But the event would count as
ionospheric in origin and have a clear signature .

It is of importance to sort reports of skewing so unusal events can be
picked out for further analysis.  Most of what I've seen reported on
the reflector can be traced to enhanced levels of magnetic/auroral
activity.  But there are others that warrant further scrutiny.  They
should be collected together, not lost in the course of time.

73,

Bob, NM7M