projection offset gps vs lcc

[Florian Lohoff]

Hi,
as i only start getting a clue about all the datum/projection problems i
am a bit stuck here. 

I got mapserver running fine with postgis and ~5GB vector Data. All
except one layer and also output projection are:

    PROJECTION
      "proj=lcc"
      "lat_1=48.6666666666667"
      "lat_2=53.6666666666667"
      "lat_0=51.0"
      "lon_0=10.5"
      "x_0=0"
      "y_0=0"
      "ellps=bessel"
      "units=m"
      "no_defs"
    END

Converted from this entry via testepsg (Which had the bug to forget
Central_Parallel as i found out after days of debugging - Now i set
lat_0 to 51.0).

PROJCS["WIGeoDE",GEOGCS["GCS_Deutsches_Hauptdreiecksnetz",
	DATUM["D_Deutsches_Hauptdreiecksnetz",
	SPHEROID["Bessel_1841",6377397.155,299.1528128]],
	PRIMEM["Greenwich",0.0],
	UNIT["Degree",0.0174532925199433]],
	PROJECTION["Lambert_Conformal_Conic"],
	PARAMETER["False_Easting",0.0],
	PARAMETER["False_Northing",0.0],
	PARAMETER["Central_Meridian",10.5],
	PARAMETER["Standard_Parallel_1",48.6666666666667],
	PARAMETER["Standard_Parallel_2",53.6666666666667],
	PARAMETER["Central_Parallel",51.0],
	UNIT["Meter",1.0]]

Now i have some GPS data i'd like to drop on top - So i converted
the GPS Data with "gen2shp" to a line shape file (Waypoints)
and added the layer like this:

    DATA "kis"

    PROJECTION
      "+proj=longlat"
      "+ellps=WGS84"
      "+datum=WGS84"
      "+no_defs"
    END

Now i have the problem that the GPS data is approx. 40m shifted West
and 200m South. Just applying an offset would be the easy task but i'd
like to get a clue whats going wrong.

Data is around lat 51.8318777 lon 8.46963456666666

Flo
PS: Debian/GNU/Linux

ii  mapserver-bin  4.4.1-2        mapserver binary utilities
ii  libpostgis1-pg 1.0.0-1        geographic objects support for PostgreSQL
ii  postgresql     7.4.7-6sarge1  object-relational SQL database management sy
ii  libgdal1       1.2.6-1        Geospatial Data Abstraction Library
-- 
Florian Lohoff                  flo at rfc822.org             +49-171-2280134
                        Heisenberg may have been here.
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