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July 25th 03, 10:52 AM

oSaddam (Yuri Blanarovich) wrote in message ...

Things I would like to see is incorporation of terrain simulation with antenna
design. Few zones of different "ground quality" (radials, sand, salt water)
with linear and/or circular boundaries plus sloping terrain (contour profile).
Example would be four square array on the sloping hill of sand some distance
from the ocean. Verticals are very sensitive to the ground quality and terrain
slopes/profile and this feature would be a great tool in quest for maximizing
the performance of array by using the terrain features (enhanced F/B).
K6STI has Terrain Analyzer (?) I have never tried it, but I understand that he
uses free space pattern of antenna and then applies the geometry and quality of
ground. I can see that more true representation of antenna's performance is to
tweak the design with real ground/terrain situation. Vertical antennas, where
ground participation makes significant difference in the tuning of array, would
be more closely modeled by using real ground rather than free space (who's got
it anyway?) and then doing optimization with given ground/terrain situation.
Enough challenge?

What a strange coincidence..., I had the same thoughts and almost used
the same words when contacting Dean Straw for an evaluation copy of
his latest HFTA terrain analysis software, to figure out if it was
possible and if it would be worth the effort to interface with this
software to optimize over a specific terrain profile and/or interface
with the VOACAP propagation prediction software.
I also took a look at TA and to see how this would fit, but because
this package is DOS based I decided to take a further look at HFTA.

However, it seems both packages are restricted to the use of
horizontal polarized (Yagi) antennas only. Because 4nec2 was created
to support also other types of antennas (there are already a number of
Yagi optimization programs) it looks like both programs would not
match completely. Furthermore, I am not such an (antenna) expert that
I can create the equations my own to determine the resultant radiation
pattern over none-flat ground for both vertial and horizontal
polarized systems. Also concerning the user-interfrace for both
programs it seems not that easy to automatically interface with one of
them.

So maybe all this will "time-out" till the long winter evenings...

Arie.