how can I convert OGC WKT to Proj4 string


PROJCS["Reykjavik 1900 / Lambert 1900",GEOGCS["Reykjavik 1900",DATUM["Reykjavik_1900",SPHEROID["Danish 1876",6377019.27,300,AUTHORITY["EPSG","7051"]],TOWGS84[-28,199,5,0,0,0,0],AUTHORITY["EPSG","6657"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4657"],AXIS["Latitude",NORTH],AXIS["Longitude",EAST]],UNIT["metre",1,AUTHORITY["EPSG","9001"]]]

  • Depending on PROJ.4 version you might be able to use "+axis wnu" but I'm not sure if that's at the command line level or in the library.
    – mkennedy
    Commented Mar 14, 2016 at 18:33

2 Answers 2


GDAL knows the Reykjavik 1900 GCS, with this parameter string:

+proj=longlat +a=6377019.27 +b=6355762.5391 +towgs84=-28,199,5,0,0,0,0 +no_defs

There are no parameters given for the Lambert projection. That might be a reason why EPSG:3052 is not implemented in Proj.4/GDAL.

The EPSG registry notes:

Latitude of natural origin  65° N
Longitude of natural origin 19° 1' 19.65" W

but no information on the projection method. It might be different from lcc and laea which are available in Proj.4/GDAL.

http://www.raunvis.hi.is/~geirf/seg/seg-ind.htm gives some hints:

"maps based on "Reykjavík 1900" datum drawn in Lambert Conformal Conic projection with one standard parallel (65° N) and the center point (x,y)=(0,0) at (65°N, 19.022°W), x pointing West at that point and y North."

So you can try these parameters:

+proj=lcc +a=6377019.27 +b=6355762.5391  +lat_1=65 +lat_0=65 +lon_0=-19.022 +x_0=0 +y_0=0 +axis=wnu +towgs84=-28,199,5,0,0,0,0 +units=m +no_defs

to get this coordinate grid, displayed on a Web Mercator background:

enter image description here

There is an online calculator at http://cocodati.lmi.is/cocodati/cocodat-i.jsp that can transform from and to Lambert 1900. It uses a 7-parameter datum transformation, which might be better than the 3-parms that GDAL uses. The offline manual from http://cocodati.lmi.is/cocodati/cocodati-manual.pdf gives some background on this, but has a typo on the dx parameter.

So lets test with cs2cs:

cs2cs +proj=lcc +a=6377019.27 +b=6355762.5391  +lat_1=65 +lat_0=65 +lon_0=-19.022 +x_0=0 +y_0=0 +axis=wnu +towgs84=-28,199,5,0,0,0,0 +units=m +no_defs +to +init=epsg:4326 -f "%%.8f" <Island-Lambert.txt >Island-wgs84.txt
cs2cs +proj=lcc +a=6377019.27 +b=6355762.5391  +lat_1=65 +lat_0=65 +lon_0=-19.022 +x_0=0 +y_0=0 +axis=wnu +towgs84=556.020,-168.701,942.364,4.154,-0.269,-2.279,-3.729 +units=m +no_defs +to +init=epsg:4326 -f "%%.8f" <Island-Lambert.txt >>Island-wgs84.txt
cs2cs +proj=lcc +a=6377019.27 +b=6355762.5391  +lat_1=65 +lat_0=65 +lon_0=-19.022 +x_0=0 +y_0=0 +axis=wnu +towgs84=556.020,-168.701,942.364,-4.154,0.269,2.279,-3.729 +units=m +no_defs +to +init=epsg:4326 -f "%%.8f" <Island-Lambert.txt >>Island-wgs84.txt

on a test point at 150000 -100000 which delivers:

-22.09304048    64.07190553 -1053.88158670
-22.09839453    64.06973810 62.39101574
-22.09264623    64.07046456 62.60636384

The online converter computes 64.070464568(N) 22.092771204(W) so the last parameter set fits best:

+proj=lcc +a=6377019.27 +b=6355762.5391  +lat_1=65 +lat_0=65 +lon_0=-19.022 +x_0=0 +y_0=0 +axis=wnu +towgs84=556.020,-168.701,942.364,-4.154,0.269,2.279,-3.729 +units=m +no_defs

The offset is about 5 meters to the East. You might have to consider tectonic moves if you need high accuracy.

  • The projection method is detailed in guidance note 7-2 - PDF as well as in the metadata of the operation method:9826. Same as LCC (1 std parallel) but coordinates are west (positive west), north rather than east, north.
    – mkennedy
    Commented Mar 14, 2016 at 18:27
  • Thanks mkennedy for the guidance note 7-2 - PDF No link to add comment to Andrej answer :) Thank you for your help Andrej this help me a lot
    – Sigster
    Commented Mar 15, 2016 at 20:45

It seems that it is not possible. It should be an easy task for gdalsrsinfo http://www.gdal.org/gdalsrsinfo.html but when I saved the OGC WKT into a text file I got just an empty result.

gdalsrsinfo ogc_wkt.txt -o proj4

PROJ.4 : ''

Propably Proj.4 does not implement some parts of that coordinate system.

  • if it was easy then spatialreferencing.org would have done it :-)
    – Ian Turton
    Commented Mar 14, 2016 at 13:38
  • Thanks for trying , WKT in Autocad and spatialreference.org are not the same will check this out
    – Sigster
    Commented Mar 14, 2016 at 14:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.