[GRASSLIST:3410] How do I annotate DRG topomaps (geo-referenced tiff files) ?
harter_d at bellsouth.net
Thu May 13 23:03:38 EDT 2004
I have some USGS DRG topographic maps that I downloaded. I want to
create a raster that has vecotr and/or site data plotted on the
topographic map. Then I will export the raster to create another DRG
topographic map that has my data plotted on it. I am wondering how to
do that. One approach would be to display the raster data, vector data
and then the site data and labels. Then use the png driver. That seems
to be only suitable for a small area not a whole 7.5" topo map. The
other approach is to use the cell driver. That generates a file but it
is not geo-referenced. If I could modify its region from (x y pixel
coordinates) back to my NAD27 topo then that might work. That is not
I thought about using mapcal. I would convert the site data to a raster
map then I could superimpose that on the topo raster. That does not
seem to work becasue there doesn't appear to be a feature to convert
site labels to raster.
What would work out best is if I could just reference my whole region
in a display where I have already plotted the vector and site data on
top of the raster, and create a raster layer of plotted data. I could
then export this layer to a geo-referenced tiff. Is there any way that
I could reference the displayed cells with site data on it so that I
could use mapcalc to create another raster layer?
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