TopBand: Refection vs. Reflaction

Ward Silver hwardsil@WOLFENET.com
Tue, 27 May 1997 11:47:02 -0700 (PDT)


> David K1TTT,
> 
> In your reply to NM7M's posting, you said
> 
> "consider a transmission from a vertical ionospheric sounder, the wave front
> is essentially a plane when it encounters the ionsphere.  now assuming that
> the ionopshere is quiet and uniformly ionized above the sounder the wave
> front will not see any gradients, but can still be reflected back down to
> the receiver."
> 
> Huh???  Are you saying that the reason the signal from a vertical sounder
> returns to earth is because it's REFLECTED from a uniform ionopshere?  Like
> a mirror?
> 
> Hopefully I misunderstood your comment.  Because the reason the signal
> returns to earth is because it's REFRACTED (bent, turned, etc) in the
> ever-increasing (up to the F region peak, of course) electron density.  If
> that doesn't constitute a gradient, I don't know what does.
> 
> Carl K9LA

What's the actual difference between reflection and refraction except that
reflection takes place over a very short distance? (i.e., close to or less
than one-wavelength)

Reflection could be said to take place at "step" type discontinuities in
the media through which the waves travel.  How "steep" a gradient is
required before refraction becomes reflection?

73, Ward N0AX


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