[Mapserver-users] Ccoordinate/projection display problem?

[Ed McNierney]

Ann -

Actually, the EPSG code IS a complete description - but you were using
the same code for all your layers in your original map file.

The EPSG code is, I think, somewhat preferable IF you are using a
standard projection.  The downside is that it's a little cryptic (a MAP
file comment would help) but the upside is that it's much harder to make
typos, and much easier to ensure that two projections that should be the
same ARE the same.

	- Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
Phone: (978) 251-4242  Fax: (978) 251-1396
ed at topozone.com


-----Original Message-----
From: Ann Keane [mailto:Ann.Keane at noaa.gov] 
Sent: Friday, September 12, 2003 7:31 PM
To: Frank Warmerdam
Cc: mapserver-users at lists.gis.umn.edu; Ed McNierney
Subject: Re: [Mapserver-users] Ccoordinate/projection display problem?


Ed and Frank-

Thank you both.  You were correct in that I was not completly describing

the coordinates and projection.  This is all well beyond what I think I 
know about cartography, so I thought the epsg code was the complete 
description.  listgeo -proj4 will be invaluable to me.  We're just 
getting started with the project so I've been using the full data files.

   The suggestions about reprojecting will be very helpful when we start

running the system operationally.

The resulting projection was:
PROJECTION
"+proj=laea +lat_0=45.000000000 +lon_0=-100.000000000 +x_0=0.000 
+y_0=0.000 +ellps=WGS84 +units=m"
END

-Ann


Frank Warmerdam wrote:

> If you have
> listgeo handy you might try running "listgeo -proj4 shdrlfi0201.tif"
to
> see what it things is a good "PROJ.4 string" representing the
coordinate
> system of the file in question.
> 
> I would guess you will want something like:
> 
> PROJECTION
>   "+proj=laea +lat_0=45 +lon_0=-100 +datum=WGS84"
> END
> 
> You can test convert points using the PROJ commandline tools something
like
> this:
> 
> warmerda at gdal2200[29]% cs2cs +proj=laea +lat_0=45 +lon_0=-100 
> +datum=WGS84 +to +proj=latlong +datum=WGS84
>  -6086629. 4488761                                    (input)
>  156d3'31.097"E        37d45'55.65"N 0.000            (output)
>