I am very new to TransDEM, like a couple days. I am working on the Royal Gorge route in the US and have a big problem. When merging the DEMS from Fremont County Colorado, I found that I had a whole in right in the center of my map. Come to find out, the DEM for "Royal Gorge" is missing from the files at http://data.geocomm.com/dem. I have searched everywhere, and can't find the DEM.
Does anyone know where or how I can get this one missing DEM? I am too new at TransDEM to know if it can be created or not.
Please help,
Thanks,
Merrill
Missing DEM Please Help
Re: Missing DEM Please Help
My recommendation is to obtain the DEMs directly from the USGS source, via the National Map portal. See here for a short tutorial: http://forum.transdem.de/viewtopic.php? ... t=20#p1172 (A few minor details are no longer quite up to date but the overall process still is.)
The data is packed into 1x1 degree chunks for 1 and 1/3 arc sec and into 15 x 15 arc min chunks for 1/9 arc sec. These are huge files but TransDEM should be able to handle them, and in the 64bit variant also merge without further ado.
Most US Trainz route builders go for 1/3 arc sec resolution.
You can choose any file format, ArcGrid, GridFloat or IMG. I suggest to download in IMG format simply because they will retire the other two eventually.
For maps, the next step after you got your DEMs, it's most probably the USGS 1:24,000 topo. Quickest way here was the WMS, as explained in the manual, however, that's gone, I'm afraid. Fortunately, we have found a replacement as a Map Tile service: http://forum.transdem.de/viewtopic.php?f=7&t=331
The data is packed into 1x1 degree chunks for 1 and 1/3 arc sec and into 15 x 15 arc min chunks for 1/9 arc sec. These are huge files but TransDEM should be able to handle them, and in the 64bit variant also merge without further ado.
Most US Trainz route builders go for 1/3 arc sec resolution.
You can choose any file format, ArcGrid, GridFloat or IMG. I suggest to download in IMG format simply because they will retire the other two eventually.
For maps, the next step after you got your DEMs, it's most probably the USGS 1:24,000 topo. Quickest way here was the WMS, as explained in the manual, however, that's gone, I'm afraid. Fortunately, we have found a replacement as a Map Tile service: http://forum.transdem.de/viewtopic.php?f=7&t=331