Le Thursday 16 October 2008 12:42:34 Christopher Schmidt, vous avez écrit : > On Thu, Oct 16, 2008 at 12:16:54PM +0200, Jacolin Yves wrote: > > Hi list, > > > > I am switching my OL baselayers to the Google Maps's one. So I have to > > change my projection for all my data to "google mercator". All my datas > > were in lambert 2 etendue (french projection, epsg code: 27572). > > > > I succed to change it for all my shapefile using ogr2ogr or gdal with the > > following process: > > add this in the epsg file : > > [code] > > # Google Mercator > > <54004> +proj=merc +lon_0=0 +k=1 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 > > +units=m +no_defs <> > > [/code] > > This is not the Spherical Mercator projection. See > http://trac.openlayers.org/wiki/SphericalMercator : [EMAIL PROTECTED] is > missing. > > > and use : > > [code] > > ogr2ogr -s_srs "EPSG:27572" -t_srs "EPSG:54004" destination.shp > > originale.shp [/code] > > > > BUT some of my datas are stored in a postgis database. I find two "epsg > > code" to add in the spatial_reference table: > > [sql] > > INSERT into spatial_ref_sys (srid, auth_name, auth_srid, srtext, > > proj4text) values (900913 ,'EPSG',900913,'GEOGCS["WGS 84", DATUM["World > > Geodetic System 1984", SPHEROID["WGS 84", 6378137.0, > > 298.257223563,AUTHORITY["EPSG","7030"]], > > AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich", 0.0, > > AUTHORITY["EPSG","8901"]], NIT["degree",0.017453292519943295], > > AXIS["Longitude", EAST], AXIS["Latitude", > > NORTH],AUTHORITY["EPSG","4326"]], > > PROJECTION["Mercator_1SP"],PARAMETER["semi_minor", 6378137.0], > > PARAMETER["latitude_of_origin",0.0], PARAMETER["central_meridian", 0.0], > > PARAMETER["scale_factor",1.0], PARAMETER["false_easting", 0.0], > > PARAMETER["false_northing", 0.0],UNIT["m", 1.0], AXIS["x", EAST], > > AXIS["y", NORTH],AUTHORITY["EPSG","900913"]] |','+proj=merc +a=6378137 > > +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m > > [EMAIL PROTECTED] +no_defs'); > > This one is right. > > > INSERT INTO spatial_ref_sys (srid, auth_name, auth_srid, srtext, > > proj4text) VALUES (54004, 'spatialreference.org', > > 54004, > > 'PROJCS["World_Mercator",GEOGCS["GCS_WGS_1984",DATUM["WGS_1984",SPHEROID[ > >"WGS_1984",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.0 > >17453292519943295]],PROJECTION["Mercator_1SP"],PARAMETER["False_Easting",0 > >],PARAMETER["False_Northing",0],PARAMETER["Central_Meridian",0],PARAMETER[ > >"Standard_Parallel_1",0],UNIT["Meter",1],AUTHORITY["EPSG","54004"]]', > > '+proj=merc +lon_0=0 +k=1 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 > > +units=m +no_defs '); [/sql] > > Don't use this one. > > > If I am using the 900913 projection, my datas are shift to the south from > > the right location. > > No. If you're using 54004, your data is shifted too far north. > > > I would like to know wich one is "the best" to use and why I have some > > difference! I am mixing all this in my mind :( > > Regards,
thanks Christopher ! So I forgot the 54005 projection code ;) I added the sql script for postgis in the wiki page you gave me. Y. -- Yves Jacolin --- http://softlibre.gloobe.org _______________________________________________ Users mailing list Users@openlayers.org http://openlayers.org/mailman/listinfo/users