Projections with ARCINFO Grids

Aaron Racicot aaronr at ECOTRUST.ORG
Wed May 4 15:18:48 EDT 2005


Hi there,

I am having issues with displaying some Arc/Info Binary Grid's.  I was hoping that I would not have to explicitly define the projection information for layers that I am dynamically adding to my mapfile since the format they are in has a prj.adf file defining the projection.  I am displaying my main map in lat-lon, but have a couple of rasters that are in different projections (such as UTM zone 10N).  If I explicitly define the projection in the map file things display fine for the layer:


  LAYER
    DATA "siuslaw/data_cd/region/shd90/"
      METADATA
      END
    NAME "siuslaw_data_cd_region_shd90"
    SIZEUNITS PIXELS
    STATUS ON
    TOLERANCE 0
    TOLERANCEUNITS PIXELS
    TYPE RASTER
    UNITS METERS
    PROJECTION
      "proj=utm" 
      "ellps=clrk66" 
      "zone=10" 
      "north" 
    END
  END


When I try to remove the projection definition from the layer and allow GDAL to get the projection info from the ArcInfo Grid itself I loose the layer on the map (I assume it is being assumed to have a lat-lon coordinate system like the main map).  When I use gdalinfo to look at the ArcInfo Grid I get the projection info just fine:


[aaronr at pearl rip_veg]$ gdalinfo hdr.adf
Driver: AIG/Arc/Info Binary Grid
Size is 3234, 2364
Coordinate System is:
PROJCS["UTM Zone 10, Northern Hemisphere",
    GEOGCS["NAD27",
        DATUM["North_American_Datum_1927",
            SPHEROID["Clarke 1866",6378206.4,294.978698213898,
                AUTHORITY["EPSG","7008"]],
            TOWGS84[-3,142,183,0,0,0,0],
            AUTHORITY["EPSG","6267"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9108"]],
        AXIS["Lat",NORTH],
        AXIS["Long",EAST],
        AUTHORITY["EPSG","4267"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",-123],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["METERS",1]]
Origin = (408851.852209,4904262.055127)
Pixel Size = (25.00000000,-25.00000000)
Corner Coordinates:
Upper Left  (  408851.852, 4904262.055) (124d 8'32.57"W, 44d17'16.24"N)
Lower Left  (  408851.852, 4845162.055) (124d 7'55.95"W, 43d45'21.02"N)
Upper Right (  489701.852, 4904262.055) (123d 7'44.69"W, 44d17'36.55"N)
Lower Right (  489701.852, 4845162.055) (123d 7'40.56"W, 43d45'40.96"N)
Center      (  449276.852, 4874712.055) (123d37'58.50"W, 44d 1'32.72"N)
Band 1 Block=256x4 Type=Byte, ColorInterp=Undefined
  Min=1.000 Max=14.000
  NoData Value=255
[aaronr at pearl rip_veg]$


Is there a way to get this to work?  I just don't want to have to do something silly like parse the gdalinfo output to be able to dynamically know what the ArcInfo Grid projection is.  

Thanks in advance!

Aaron

My System:
Fedora Core 3
Mapserver 4.4.2 (php Mapscript)
GDAL 1.2.5

MapServer version 4.4.2 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP SUPPORTS=PROJ SUPPORTS=FREETYPE SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER SUPPORTS=WFS_CLIENT INPUT=EPPL7 INPUT=SDE INPUT=POSTGIS INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE DEBUG=MSDEBUG

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| Aaron Racicot  | aaronr at ecotrust.org   |
| GIS Programmer | 503.467.0759          |
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