Reg Edwards wrote:
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It has just occurred to me that the loss due to ground reflections may
be related to the angle at which waves strike the earth. It is the
same angle as the transmit elevation angle and can be quite small.
----
Reg.

The amplitude and phase of a field after ground reflection depends on
the polarization, and is quite different for horizontal and vertical. It
of course also depends on ground conductivity and permittivity,
frequency, and angle. The equations are simple, and can be found in
Kraus and other references. Those equations are used by NEC for
determination of the far field pattern.

Roy Lewallen, W7EL