I need to be able to lay USGS contours over a drawing of a large tract of land, or use a quad sheet as a backsground map in Terramodel. Problem is it needs to be scaled to about 1"=500', and when I download anything I've found so far and blow them up, they are too fuzzy at that scale. Any sources for high quality maps would be appreciated.
Is the quad in KY? Which one? Do you need the entire quad or just a small portion?
Bring it into CAD, do the onscreen digitizing thing, with the scale where you can see it. Make sure to digitize in some "control" for the transformation.
Then scale up the digitized contours.
Also, around here, I can find a CAD file of the contours, roads and ponds already digitized from quad maps.
:coffee:
I don't know if these will work any better for you,
but here is an option I like to use:
Try this, maps available for the entire us:
http://libremap.org/
click "data"
choose your state
click "View the entire list of USGS Pennsylvania Digital Raster Graphic Maps"
then choose the quad you're looking for.
enjoy!;-)
It's in Ky, of course it spans 2 quads.
If you let me know which ones, I can check if we have them. The company I work for sells digital quads in dwg format (used to be a big business with coal and timber companies). We have a great number of quads in WV, KY, OH, PA and VA among other states.
Thanks, I think I've got it from JP's link.
In my opinion, USGS maps are not well rectified, especially NAD 83 maps.
I know a bunch of folks over in Rolla with USGS that have retired.
Very smart people.
They did a lot of gyrations with Blue Marble to rectify the 7.5' quadrangles
but I do not like the results. The best way that I have found is to GPS locate
four map identifiable points like road intersections near the corners of the
quadrangle, then calibrate the map to the GPS points.
