[TowerTalk] HFTA Disc....

[N3AE]

Dave, 

According to Dean, HFTA has a terrain pre-smoothing algorithm internally which is applied to the raw elevation profile provided by the user. Unfortunately, HFTA does not give you the opportunity to plot what this smoothing filter has done to your elevation profile. Probably in a great majority of situations, the pre-smoothing algorithm doesn't make the results overly sensitive to the specific elevation profile. But in my case with the terrain bounding up and down like a washboard, what the smoothing algorithm is doing "may" make a big difference. 

Ian suggests getting by the 149 point limit by manually editing out large shadow areas, etc. Good idea if you can be sure they are indeed shadow areas and refracted signals are not getting into them. Personally, I'd be at a loss to come up with rules for such manual editing of elevation profiles except in simple situations like a nearby large body of water with mountainous terrain on the other side. 

Shawn 
N3AE