# [Proj] MapInfo coordsys to proj.4 syntax

Paul Surgeon surgpub at telkomsa.net
Mon Jun 5 18:00:25 EDT 2006

```I'm trying to convert a MapInfo coordinate system into something that proj.4
understands but my high school maths doesn't seem to be helping me much.

The TAB files look like this :
Type "RASTER"
(830000.00,2050000.00) (0,0) Label "Pt 1",
(840000.00,2050000.00) (2000,0) Label "Pt 2",
(840000.00,2040000.00) (2000,2000) Label "Pt 3",
(830000.00,2040000.00) (0,2000) Label "Pt 4"
CoordSys Earth Projection
3,1002,7,0,46.8,45.898918964419,47.696014502038,600000,2200000
Units "m"

I've read some MapInfo docs and managed to break it down to :
Name of projection = CoordSys Earth Projection 3
Projection type = 3 = Lambert Conformal Conic
Datum = 1002 = NTF (Paris)
Ellipsoid = Modified Clark 1880
Units = 7 = meters
Origin lon = 0 (central meridian)
Origin lat = 46.8
Standard parallel 1 = 45.898918964419
Standard parallel 2 = 47.696014502038
False Easting = 600000
False Northing = 2200000

I tried to use one of the standard NTF (Paris) EPSG definitions as a base to
work from but that doesn't seem to work.

My attempt :
+proj=lcc +lon_0=0.0 +lat_0=46.8 +lat_1=45.898918964419 +lat_2=47.696014502038
+k_0=0.99987742 +x_0=600000 +y_0=2200000 +a=6378249.2 +b=6356515
+towgs84=-168,-60,320,0,0,0,0 +pm=greenwich +units=m +no_defs

I assigned this srs definition with gdal_translate and then used gdalwarp to
warp the raster into a standard UTM zone.
However I must be really far out with the proj.4 syntax because when I try to
lay the resulting raster over another it's so far out that I can't identify
anything common between the two images.

Any ideas where I'm going wrong?
Paul
```