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Date: Fri, 17 Dec 1999 18:24:54
To: rsgb_lf_group@blacksheep.org
From: "Rik Strobbe" <rik.strobbe@fys.kuleuven.ac.be>
Subject: Re: LF: Re.LF 162Khz field strength.
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At 15:19 17/12/99 -0000, you wrote:
>Relating all this to the possibility of transatlantic QSOs it seems that
there 
>will be no ground wave so we are only concerned with the reflected wave and 
>therefore the height of the ref.layer,but at only 60-80Kms the number of
hops 
>will be very great and thus the distance the waves have to travel!  
>can anybody do the spherical geometry to work this out?

As far as I remind my maths the 'skip distance' should be :

 D = 2 x 111 x arccos( R/(R+H))

Where D = skip distance (km), R = earth radius (6366km), H = layer height
(in km).

For a height of 60km the skip distance would be 1724km, for a height of
80km it would be 1988km.

But the above assumes that the take-off angle is 0 degrees. Since vertical
polarized signals at this frequency tend to 'bend' arround the earth
(groundwave) they might not (or very little) escape into the 'sky'. If you
have higher radiation angles then the skip distance becomes considerably
shorter.

73, Rik  ON7YD