I use nautical twilight, solar elevation -12 degrees. The dark side
of which is a reasonable approximation to when "F" layer illumination
is lost. Or so I am advised.
On 01/09/2006 09:29:17, Beau (n9mfk@...) wrote:
> hello all I have a quick question abot the gray line settings in dx
> atlas it gives me a choice of using civil twilight or nautical
> twilight or astronomical twilight which one of these do I went to
> use to get the most out of Gray line propagation thanks Beau