[Xastir] Datum conversions

[Curt Mills]

On Sun, 19 Dec 2004, Tom Russo wrote:

> Unfortunately, the numbers you show above don't look like they're UTM
> coordinates for the area you're saying they represent.  Longitude 112W is
> right at the boundary of UTM zone 12, and if I try to convert 112.8W, 53.5N
> to UTM in zone 12 with cs2cs (from the proj4 install) I get
> 380607.21Easting,5929401.53Northing --- nothing like the numbers you show
> above.  So I can't even begin to guess what projection is used (could be
> just about anything).

State Plane coordinates, in feet?

I've had good luck reading those types of files in with OGR.
Unfortunately if you switch the Shapefile drawing over to OGR you
end up losing the dbfawk functionality, plus you don't have all the
hard-coded defaults in there of the non-dbfawk original Shapefile
code.  This makes the maps ugly, but perhaps still useful for you.
There's a #define in the code you can use to make this switch, if
you want to try it.  Weather Alert shapefiles still go through the
old code in any case, so that you don't lose those.

Your best bet though would be to use ogr2ogr to convert to something
that the regular code could handle.  How to get there is the trick,
when you don't know what you're starting from.

-- 
Curt, WE7U.				archer at eskimo dot com
http://www.eskimo.com/~archer
  Lotto:  A tax on people who are bad at math. - unknown
Windows:  Microsoft's tax on computer illiterates. - WE7U.
The world DOES revolve around me:  I picked the coordinate system!"