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Re: [TowerTalk] Trees, Mountains, 15 degrees...

To: "Michael Tope" <>,"Pat Barthelow" <>, <>,<>
Subject: Re: [TowerTalk] Trees, Mountains, 15 degrees...
From: Pete Smith <>
Date: Mon, 24 Jan 2005 21:23:52 -0500
List-post: <>
I think the number of points Mike cites is correct, and that the 3 mile figure is assuming 100 feet per interval, or about 30M, which is the horizontal resolution of the USGS DEM data. It seems reasonable that if you had Mount Everest 20 miles away it would have an effect, and I expect that's true for lesser mountains too.

73, Pete N4ZR

At 08:36 PM 1/24/2005, Michael Tope wrote:

> However, Jim did say "a few miles" away.  HFTA, N6BV's terrain analysis
> software for the ARRL, only includes terrain out to about 3 miles in its
> calculations.  The shape of the terrain obstruction can also make a
> substantial difference in how much impact it will have.
> All that being said, 15 degrees... wow.
> 73, Pete N4ZR

Pete are you sure that is correct? I thought HFTA would do 149 terrain
points at whatever spacing provided, the tradeoff being fine structure
detail versus distance covered.

Mike, W4EF........................


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