TransDEM Forum

hi everyone. i was working on getting camas prairie looking proto as much as possible tome as i could. but when i was working on the 3% grade the track and the terrain didnt match up. so i tried to get the dem at the right hight n transdem but when i thought i got it it wasnt even close. can anyone help me please? thanks -inprr

Which DEM source do you use?

i think its the strm84 dem.

For a US route I recommend NED DEMs. They have the better resolution. The 1/3 and 1/9 arc sec variants will form cuttings and embankments/high fills and should yield proper gradients. See here for a very detailed tutorial: http://forum.transdem.de/viewtopic.php?f=6&t=57. (Careful with 1/9 arc sec though. Requires an awful amount of memory.)

And here for a comparison of US DEMs: http://forum.transdem.de/viewtopic.php?f=2&t=24. The last two images should give you an idea of what to expect from the railroad right-of-way in the NED DEM.

i have looked for the web site and am unable to find it. the one that's given doesnt work for me can you help me please? thanks -inprr

The tutorial has a mistake in the web address as I just noticed. Part 1, page 1: The correct address of Seamless Server is http://seamless.usgs.gov/, without "www".

thanks for your help geophil. i was able to get CSP going in the right direction for a change. if i wanted to sell the route do i need a license to sell it or any other route made from transdem? thanks again -inprr

Yes. You would need the commercial TransDEM license. Contact me by email for details.