Trouble with Projection - LCC

[Ed McNierney]

Jim -

I suspect it's printing about 3.281 times larger in each dimension than you expect.....

You're not telling MapServer that your input projection units are feet, rather than the default value of meters.  Therefore, the coordinates are being read as if they were meters, moving them 3x further from the projection origin in X and Y.

That's what the UNITS field in the PRJ file is telling you - what to multiply the coordinate values by to convert them to meters.  You need to add:

    to_meter=0.3048006096012192

in your projection definition block.

You don't need the a= and rf= lines and I suggest you remove them; ellps=GRS80 specifies the ellipsoid completely.

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




From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] On Behalf Of Shanton, James A
Sent: Friday, November 19, 2004 9:13 AM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: [UMN_MAPSERVER-USERS] Trouble with Projection - LCC


I'm trying to plot a property parcel shp file, and it keeps plotting in Pennsylvania instead of North Carolina.
It also prints out the wrong size.  (much to big )

I've posted my parcel layer (from the .map file )  and the PRJ file that came with the shp file.
What am I doing wrong ?

My map file output projection is :
PROJECTION
  "proj=longlat"
  "ellps=WGS84"
END

Thanks !

Jim
-------------------------------------------------------------------------------------

LAYER # PARCELS
  NAME "parcel"
  DATA parcel
  STATUS ON
  TYPE POLYGON
  PROJECTION
     proj=lcc
     lat_0=33.75              #Latitude of False Origin
     lon_0=-79.0              #Longitude of Natural Origin (Central Meridian)
     lat_1=34.33333333333334  #Latitude of First Standard Parallel
     lat_2=36.16666666666666
     x_0=2000000.002616666    # False Easting
     y_0=0.0                  # False Northing
     ellps=GRS80              # SPHEROID
     a=6378137.0              # from SPHEROID["GRS_1980",6378137,298.257222101]],
     rf=298.257222101         #from SPHEROID["GRS_1980",6378137,298.257222101]],
     datum=NAD83
  END
  CLASS
            OUTLINECOLOR 0 0 0
  END
END # end of Parcel layer



Here is the PRJ file

PROJCS["NAD_1983_StatePlane_North_Carolina_FIPS_3200_Feet",
GEOGCS["GCS_North_American_1983",
DATUM["D_North_American_1983",
SPHEROID["GRS_1980",6378137.0,298.257222101]],
PRIMEM["Greenwich",0.0],
UNIT["Degree",0.0174532925199433]],
PROJECTION["Lambert_Conformal_Conic"],
PARAMETER["False_Easting",2000000.002616666],
PARAMETER["False_Northing",0.0],
PARAMETER["Central_Meridian",-79.0],
PARAMETER["Standard_Parallel_1",34.33333333333334],
PARAMETER["Standard_Parallel_2",36.16666666666666],
PARAMETER["Latitude_Of_Origin",33.75],
UNIT["Foot_US",0.3048006096012192]]
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