[Mapserver-users] Ccoordinate/projection display problem?

[Gerry Creager N5JXS]

I've been swamped, and consequently lost some of this thread.  I'm 
*still* haveing projection problems, so I'll ask again.  Maybe I'll 
understand what's going on...

If, in my mapfile I want to have the final projection in Lambert 
Conformal Conic, but all of my data are Lat/Lon unprojected, then, the 
PROJECTION section of the top layer is LCC, while the projection info in 
all the layers would be LAT-LON?  Or is this inverted?

Confusedly yours,
Gerry

Ed McNierney wrote:
> 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)
>>
> 
> 
> 
> 
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-- 
Gerry Creager -- gerry.creager at tamu.edu
Texas Mesonet -- AATLT, Texas A&M University	
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