[Xastir] Re: topo maps

[Curt, WE7U]

On Mon, 1 Mar 2004, Bennett, Bruce wrote:

> It's actually much less effort just to edit an .fgd file to alter it
> for the coodinates of each map. This is the voice of experience speaking
> here :)
>
> The coordinates are listed in the four corners of each map image.

Actually the only part of the FGD file that Xastir needs/looks for
is the part containing the four corner coordinates.  The rest can be
missing.


> What I am wondering is why the .fdg is needed at all, since the tif file
> contains the map coodinates - can't the masking be done based upon the
> tif info? Is some key portion missing??

Yes.  If you have a white map collar, like all the USGS ones do, you
have no way to determine where the four corner points are for the
non-collar portion of the map other than using the fgd file or
trying to figure out the coordinates from the filename.  In Xastir I
used those corner coordinates to crop off the map collar and to
stretch the map into more of a rectangle.  Without those
coordinates you can't chop off the map collar, and can't have
contiguous topo maps.

--
Curt, WE7U			    archer at eskimo dot com
Arlington, WA, USA		http://www.eskimo.com/~archer
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