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Topband: One Way Propagation

To: <topband@contesting.com>
Subject: Topband: One Way Propagation
From: nhp@ieee.org (Nick Hall-Patch)
Date: Thu, 14 Feb 2002 20:26:06 -0800
At 11:44 AM 1/29/02 -0700, W7DD wrote:
>I have heard that "One Way Propagation" has been found to be caused by heavy
>seas.  The shape of the waves formed by high wind causes the phenomena.  The
>old "over the horizon" radar is where this was first noticed.  They were
>getting false directions because of this phenomena.  Does anyone know
>anything about this?

I was waiting for other replies about this, but have seen none, so here is
the 2 cents worth:

>From what I recall, the wavelength of the heavy seas is important; the over
the horizon radar sees a strong reflection from seas with the same
wavelength as the transmitted signal, along with a Doppler shift depending
on the direction of the wavefronts.  If the seas have a different
wavelength, then there isn't much reflection.   

If there is anything in the literature about heavy seas affecting radio
propagation (as opposed to radar returns), I would like to hear more about it.

best wishes,

Nick

VE7DXR


****************************************************************************
Nick Hall-Patch
Victoria, B.C. 
Canada

e-mail: Nick_Hall-Patch@telus.net
(mail forwarded via nhp@ieee.org)

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