Re: [IRCA] Ionosphere

[Russ Edmunds <wb2bjh@xxxxxxxxx>]

--- Craig Healy <bubba@xxxxxxxxxxxxxxxxxxxx> wrote:

> >
> > I've noticed this as well... although the increased geomagnetic
> activity
> > caused expansion of the auroral oval and increased absorption
> within it,
> > more southerly paths that skirt the auroral zone can actually be
> enhanced.

*** Often the answer for this is almost "too" simple - when absorption
is occurring, the overall ambient signal levels are reduced. What was
once interference is reduced, leaving anoher signal apparently
enhanced. 


 
> There's no reason why the ionospheric layers need be perfectly
> smooth.  


*** Absolutely! It is not a smooth edge, nor is it's desnity regular.
Sometimes we're dealing with multiple refractions, sometimes a mix of
refraction and reflection. And all of that can be subject to a varying
MUF.

Add to that the fact that over a given signal path from transmitter to
receiver there may be multiple propagation modes going on as well as
potentially multiple refractions due to the irregularities in the
absorption.


Russ Edmunds
Blue Bell, PA  ( 360' ASL )
[15 mi NNW of Philadelphia]
40:08:45N; 75:16:04W, Grid FN20ID
<wb2bjh@xxxxxxxxx>
FM: Yamaha T-80 & APS9B @15'
AM: Hammarlund HQ-150 & 4' FET air core loop

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 
_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
http://arizona.hard-core-dx.com/mailman/listinfo/irca

Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers

For more information: http://www.ircaonline.org

To Post a message: irca@xxxxxxxxxxxxxxxx