[Xastir] Re: [Xastir-dev] New stuff

[Gerry Creager]

OK, so I've not downloaded and reviewed the new stufff yet, but how are 
you evaluating the error with UTM?  If it's vice TIGER, the errors 
associated with the projection against a lat/lon unprojected view are 
significant.

Curt Mills, WE7U wrote:
> Latest stuff in the CVS version:
> --------------------------------
> 
...
> Downside:
> 
> New bug found in the UTM conversion in Xastir.  It's off by about
> 100 meters in my area.  We'll figure this out and get this bug
> squashed too.  Just so everybody's aware of it.  Use the Perl script
> instead if 100 meters is critical to you.  The script output matches
> the numbers my GPS comes up with.


I'll try to look at this and see where things are falling out.  I've got 
to revisit some things:  I think I can now display my local benchmark 
and monument database (MapInfo-generated SHP file) so, if it works and I 
can see stuff I have real accurate data to compare against.

In looking at your explanation, however, a thought just hit.

UTM anticipates a mercator projection.  GPS implies LAT/LON unprojected 
("geographic projection").  There whall be variance, and you're up where 
it's more accentuated.

Gerry