Where can easily I get USGS DRG's and NHD extracts?
Posted 19 October 2012 - 04:33 PM
Well Seamless is finally dead and gone and I'm now forced to sue the National Map Viewer which looks to work in a similar fashion, albeit with more steps (progress right?). The problem is most of the files I extract are broken (GeoTIFS don't seem to work in Arc across the board), or take waaaaay too long to get (NHD data may take 2 days to be extracted fr a single quad!), and Topos are GeoPDFs which don't work with ArcGIS.
I want to know two things: 1) am I the only person who, if the National Map Viewer was a person, would be convicted of homicide by now? and 2) do you know where I can get free USGS topos as GeoTIFs or NHD extracts by quad?
GIS Reference and Instruction Specialist, Stanford Geospatial Center.
Posted 19 October 2012 - 05:31 PM
Posted 21 October 2012 - 09:05 AM
The latter source only covers quadrangles that include US national forests (which would include Jim Jam Ridge), and is likely to be more recent and accurate.
Forest Service maps don't include vegetation, but for some forests you can find that as a separate shapefile. When a vegetation shapefile isn't available, we extract the vegetation layer from the USGS quadrangle geoTIFF using Photoshop, clean it up, and merge it into the Forest Service map.
2i3D Stereo Imaging
Posted 21 October 2012 - 01:37 PM
Thank you for that link, Redbeard! It's also a superior source for seamless digital elevation models.
Not to mention you could get the vegetation from a dataset such as usgs NLCD or the Corine land cover in europe. The folks at development seed used GLOBCOVER did when creating their latest terrain maps.
Whoever wrote the interface, though, didn't understand the notation for arcseconds. We're given the opportunity to download 1 inch and 1/3rd inch DEMs.
Posted 24 October 2012 - 12:48 PM
Some real UX problems there.
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