Cecil Moore wrote:
Ian White, G3SEK wrote:

Dale Parfitt wrote:
The ARRL Antenna Handbook describes ground wave as:"...any wave that
stays close to the earth, reaching the receiving point without
leaving the earth's lower atmosphere."

That definition is very misleading at VHF, since normal tropospheric
refraction takes place entirely in "the earth's lower atmosphere" but
generally doesn't involve ground at all. It's a gradual bending of the
space wave.

Yep, the IEEE Dictionary says the "ground wave" possesses a
space wave component. "From a source in the vicinity of the
surface of the Earth, a wave that would exist in the vicinity
of the surface in the absence of an ionosphere. The ground wave
can be decomposed into the Norton surface wave and a space wave
consisting of the vector sum of a direct wave and a ground-
reflected wave."

Thank you - that's a new one to me.

So what does the IEEE define a "Norton surface wave" to be?


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek