[TowerTalk] Ground level and sea level

[Tom Rauch]

 > I think it is relevant to those of us who live in very
flat
> areas such as most of Florida where storm surge is
relevant.

OK for storm surge. It has meaning. Unless you're worried
about tidal surges, anything else really should be height
above surrounding terrrain.

> Otherwise, it may be relevant as a common point of
reference
> re. topography, e.g. if I told you that the grade on my
property
> sloped in various directions and my 60 foot tower was at a
high
> point of 40 feet above sea level and that the 55 foot tree
to
> which I want to stretch a 160M antenna crossed a shallow
ravine
> 15 feet above sea level to a a point 30 feet above sea
where the
> tree stood would that not help you to visualize the
terrain
> below the antenna which may or may not impact NVIS or
other
> characteristics?

That would be good too, but you gave info about the
surroundings.

What seems to happen is someone says "I have an antenna that
is 991 ft ASL so it........." Fill in the blank with you
want. There isn't any reference to what's around it.

I can't visualize if it is in a hole 500 feet deep or on top
of a 500 ft steeply sloped rise.