[FWTools] projecting with ogr2ogr v. ArcInfo

[Bryan Keith]

Hello,

I'm attempting to project data from geographic coordinates to a 
Minnesota county coordinate system (Hennepin County) using ogr2ogr and 
ArcInfo.  The results are slightly different, and I'm not sure why.  X 
coordinates are about the same (within 0.1 feet), but Y coordinates 
differ by ~3.1 feet.  This difference seems consistent though I haven't 
verified that thoroughly.  I include a small subset of the points in 
this e-mail.

Input coordinates are long-lat:

-93.17356183         45.04758353
-93.36960993         45.08857070
-93.27394885         44.97432735

Output from ogr2ogr:

554221.66861940 193587.15836056
503544.69316568 208462.19508218
528309.75142366 166825.34464421

Output from ArcInfo:

554221.6767         193584.0575
503544.6937         208459.0942
528309.7556         166822.2438

ogr2ogr info:

ogr2ogr -t_srs "+proj=lcc +lat_1=44.88333333333333 
+lat_2=45.13333333333333 +lat_0=44.79111111111111 
+lon_0=-93.38333333333334 +x_0=152400.3048 +y_0=30480.06096 
+a=6378418.941 +b=6357033.31 +to_meter=0.3048006096012192 +no_defs" 
-s_srs geo.wkt hen_pt.shp geo_pt.shp

where geo.wkt is:

GEOGCS["NAD83",
    DATUM["North_American_Datum_1983",
        SPHEROID["GRS 1980",6378137,298.257222101,
            AUTHORITY["EPSG","7019"]],
        TOWGS84[0,0,0,0,0,0,0],
        AUTHORITY["EPSG","6269"]],
    PRIMEM["Greenwich",0,
        AUTHORITY["EPSG","8901"]],
    UNIT["degree",0.0174532925199433,
        AUTHORITY["EPSG","9108"]],
    AXIS["Lat",NORTH],
    AXIS["Long",EAST],
    AUTHORITY["EPSG","4269"]]

ArcInfo info:

Arc: project file geo.txt hen.txt geo_hen.prj

where geo_hen.prj is:

INPUT
Projection GEOGRAPHIC
Spheroid GRS1980
Units DD
Parameters
OUTPUT
projection lambert conformal conic
units feet /*by default this is US foot
parameters 6378418.941 6357033.310
44.8833333333
45.1333333333
-93.3833333334
44.7911111111
152400.3048
30480.0610
END

Does anyone know why these two coordinates transformations are yielding 
different results?

Bryan

Bryan Keith
GIS Specialist
Geomega, Inc.
Boulder, CO, USA