If there are significant changes in terrain within those increments of
295 feet it will have a significant effect on the results, at least as
far as HFTA is concerned. I've proven that to myself several times by
generating dummy terrain profiles (easy to do since they are just
columns of text) with slightly different features and comparing the
resulting plots. As you might imagine that's a function of wavelength,
so as little as ten feet difference in elevation on 20m can be significant.
73,
Dave AB7E
Pete Smith wrote:
> There's some question in my mind about how well
> these data will work with HFTA. The horizontal
> resolution of the data appears to be 3
> arc-seconds, which is 1/1200th of a degree of
> latitude and longitude, or about 90 meters (295
> feet). I don't know what effect this relatively
> low resolution, relative to HF wavelengths, may have on HFTA. Dean???
>
> 73, Pete N4ZR
>
>
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