[Xastir-Dev] problem with drg geotiff maps

[Curt Mills, WE7U]

On Wed, 30 Oct 2002, J. Lance Cotton wrote:

> Yes, Sorry. Still doesn't draw the DRGE.

Just figured out that they use a proprietary compression format
called MrSid for the DRG-E files.

Here's a blurb from a MicroDEM web page that talks about them.
Looks like you might be able to convert them to standard geoTIFF
files:


"See: http://wgiac.state.wy.us/wsdc/usgs/drg/AboutDRG.html for topo
maps in DRG format.

See: http://wgiac.state.wy.us/wsdc/drg-e/index.html for the topo
maps in DRG-E format. You can download the quads at 1:24,000 scales
in MrSid (DRG-E) or GeoTiff (DRG) format. Save the DRG-Es in Geotiff
format using the MrSid viewer.  Check metadata and note that the
coordinates are in UTM on the NAD27."


You might give it a try and see if it works.  If so, I'll add some
stuff to the README.1ST file about this map format.

Be careful of the NAD27/NAD83 difference.  It's possible that the
converted files might be off by a datum shift when used with Xastir.

-- 
Curt Mills, WE7U                    hacker_NO_SPAM_ at tc.fluke.com
Senior Methods Engineer/SysAdmin
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