[TowerTalk] tool to retrieve data and build HFTA profiles

[Jim Lux]

On 3/5/12 1:09 PM, David Aslin wrote:
> Jim, this will be hugely valuable. As someone else has posted, maybe the
> profiles should have data restricted to just sufficient to feed HFTA.
> I'll add my congratulations on a great idea and what will be a great
> service to this group; and I'll raise you a further congratulations for
> working with the SRTM data so non-US based users can enjoy the fun too!

The challenge is getting the SRTM data easily..

However it does look like a url of something like:
http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/Eurasia/N51E000.hgt.zip

should work for the 3 arc second data.

I think initially, I'd stick with letting the user specify which zone:
Africa
Australia
Eurasia
Islands
North_America
South_America

although I suppose one could do a pretty simple test.. try each one in 
turn for a given 1x1 degree tile.  I don't think they're internally 
trimmed.. (I'll have to look at the boundary line between NA and SA)

>
> Even with the 90m resolution limitation of SRTM it will be much better
> than no guidance or using flat terrain antenna data for obviously hilly
> ground; we could always stare at a map and manually interpolate the
> profile numbers, I guess.
> 73