[Xastir] USGS DRG maps again

[Curt Mills, WE7U]

On Mon, 5 May 2003, J. Lance Cotton wrote:

> Hi. I seem to be having problems with USGS DRG Geotiff maps again.
> 
> These are real DRG's, not the DRG-E's. They don't draw and no errors appear on 
> the console.
> 
> I removed the  map index file and re-indexing includes the maps in the index, 
> but they don't draw. Something looks fishy with the index bounds. Here is an 
> excerpt of map_index.sys:
> 
> 0000000000,0000000000,0000000000,0030194906,00000,0,1,filled/usgs_drg/30096e2.tif
> 0000000000,0000000000,0000000000,0030149903,00000,0,1,filled/usgs_drg/30096e3.tif

The above aren't named properly (not per USGS standards), as far as I
can tell.  They should start with a lower-case letter, which
specifies the map scale.


> 0000000000,0000000000,0000000000,0030194906,00000,0,1,filled/usgs_drg/o30096c2.tif
> 0000000000,0000000000,0000000000,0030149903,00000,0,1,filled/usgs_drg/o30096c3.tif

These are 24k maps (7.5 minute scale).  Naming appears right anyway.


> Those first few columns shouldn't be zero, right?

Correct.


> Sample of the maps at:
> http://www.lightningflash.net/~jlc7944/drg_samples.tar.gz
> (about 1.8 MB)

Takes longer than I want to dedicate to download something like that
over my dial-up.

can you bring them up in XV or using "display" and have them display
properly?  I'm just wanting to check that they have a map collar and
that they aren't MrSID compressed or anything silly like that.


> The fgd file appears correct (excerpt below):
> <begin excerpt>
> -Spatial Domain-
> 
>   Bounding Coordinates
> 
> 1.5.1.1   WEST BOUNDING COORDINATE:  -96.375000
> 
> 1.5.1.2   EAST BOUNDING COORDINATE:  -96.250000
> 
> 1.5.1.3   NORTH BOUNDING COORDINATE:  30.500000
> 
> 1.5.1.4   SOUTH BOUNDING COORDINATE:  30.375000
> 
> <end excerpt>

Yep, that looks ok to me.

Curt, WE7U.				archer at eskimo.com
http://www.eskimo.com/~archer
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