[TowerTalk] Where to get HFTA Software

[Ian White GM3SEK]

Pete Smith N4ZR wrote:
> What MicroDEM does, if used according to the instructions, is to draw 
>radials from the antenna location out some 3-4 miles, which are 
>readable by HFTA as .pro profiles.  These radials are simply the 
>electronic equivalent of drawing pencil lines on a topographic map and 
>entering the elevation at, say, 10-meter intervals

The database method will produce a table with rounded, uniform numbers 
in the distance column and interpolated heights; but when using a local 
topographic map it's probably easier to do it a different way.

Lay out your ruler along the desired beam heading, with zero at the 
antenna location, and then measure where each contour line crosses the 
scale. That creates a table with odd, variable steps in the distance 
column but uniform round numbers in the height column. HFTA doesn't mind 
either way.

You may have to do some local editing anyhow. Since SRTM used microwave 
radar, it reports dense treetops as "ground level"... which is not a 
mistake an oldtime surveyor on his horse would have made. By all means 
use your own eyes and local knowledge, and edit the height data 
accordingly.


-- 

73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek