Geodetic CRS: NTF
Datum: Nouvelle Triangulation Francaise
Ellipsoid: Clarke 1880 (IGN)
Prime meridian: Greenwich
Data source: EPSG
Information source: Institut Geographique National (IGN) document NTG_88.pdf, "Grille de parametres de transformation de coordonnees". http://www.ign.fr
Revision date: 2025-10-31
Scope: Transformation of coordinates at 1m level of accuracy.
Remarks: Parameter file is from NTF to ETRS89-FRA [RGF93 v1] (code 9327), assuming that ETRS89-FRA [RGF93 v1] is equivalent to ETRS89-FRA [RGF93 v2b] within the accuracy of the transformation. May be emulated using NTv2 method - see CT code 9891.
Method: Geocentric translations (geog2D domain) by grid (IGN)
Area of use: France - onshore - mainland and Corsica.
Description: (0,)
Definition: OGC Well Known Text 2 (2019)
COORDINATEOPERATION["NTF to ETRS89-FRA [RGF93 v2b] (1)", VERSION["IGN-Fra 1m"], SOURCECRS[ GEOGCRS["NTF", DATUM["Nouvelle Triangulation Francaise", ELLIPSOID["Clarke 1880 (IGN)",6378249.2,293.466021293627, LENGTHUNIT["metre",1]]], PRIMEM["Greenwich",0, ANGLEUNIT["degree",0.0174532925199433]], CS[ellipsoidal,2], AXIS["geodetic latitude (Lat)",north, ORDER[1], ANGLEUNIT["degree",0.0174532925199433]], AXIS["geodetic longitude (Lon)",east, ORDER[2], ANGLEUNIT["degree",0.0174532925199433]], ID["EPSG",4275]]], TARGETCRS[ GEOGCRS["ETRS89-FRA [RGF93 v2b]", DATUM["Reseau Geodesique Francais 1993 v2b", ELLIPSOID["GRS 1980",6378137,298.257222101, LENGTHUNIT["metre",1]], ANCHOREPOCH[2019]], PRIMEM["Greenwich",0, ANGLEUNIT["degree",0.0174532925199433]], CS[ellipsoidal,2], AXIS["geodetic latitude (Lat)",north, ORDER[1], ANGLEUNIT["degree",0.0174532925199433]], AXIS["geodetic longitude (Lon)",east, ORDER[2], ANGLEUNIT["degree",0.0174532925199433]], ID["EPSG",9782]]], METHOD["Geocentric translations (geog2D domain) by grid (IGN)", ID["EPSG",1087]], PARAMETERFILE["Geocentric translation file","gr3df97a.txt"], INTERPOLATIONCRS[ GEOGCRS["ETRS89-FRA [RGF93 v2b]", DATUM["Reseau Geodesique Francais 1993 v2b", ELLIPSOID["GRS 1980",6378137,298.257222101, LENGTHUNIT["metre",1]], ANCHOREPOCH[2019]], PRIMEM["Greenwich",0, ANGLEUNIT["degree",0.0174532925199433]], CS[ellipsoidal,2], AXIS["geodetic latitude (Lat)",north, ORDER[1], ANGLEUNIT["degree",0.0174532925199433]], AXIS["geodetic longitude (Lon)",east, ORDER[2], ANGLEUNIT["degree",0.0174532925199433]]]], OPERATIONACCURACY[1.0], USAGE[ SCOPE["Transformation of coordinates at 1m level of accuracy."], AREA["France - onshore - mainland and Corsica."], BBOX[41.31,-4.87,51.14,9.63]], ID["EPSG",9889], REMARK["Parameter file is from NTF to ETRS89-FRA [RGF93 v1] (code 9327), assuming that ETRS89-FRA [RGF93 v1] is equivalent to ETRS89-FRA [RGF93 v2b] within the accuracy of the transformation. May be emulated using NTv2 method - see CT code 9891."]]
Definition: PROJ.4
+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=push +v_3 +step +proj=cart +ellps=clrk80ign +step +proj=xyzgridshift +grids=fr_ign_gr3df97a.tif +grid_ref=output_crs +ellps=GRS80 +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1
Definition: JavaScript (Proj4js)
proj4.defs("EPSG:9889","+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=push +v_3 +step +proj=cart +ellps=clrk80ign +step +proj=xyzgridshift +grids=fr_ign_gr3df97a.tif +grid_ref=output_crs +ellps=GRS80 +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1");
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "Transformation", "name": "NTF to ETRS89-FRA [RGF93 v2b] (1)", "source_crs": { "type": "GeographicCRS", "name": "NTF", "datum": { "type": "GeodeticReferenceFrame", "name": "Nouvelle Triangulation Francaise", "ellipsoid": { "name": "Clarke 1880 (IGN)", "semi_major_axis": 6378249.2, "semi_minor_axis": 6356515 } }, "coordinate_system": { "subtype": "ellipsoidal", "axis": [ { "name": "Geodetic latitude", "abbreviation": "Lat", "direction": "north", "unit": "degree" }, { "name": "Geodetic longitude", "abbreviation": "Lon", "direction": "east", "unit": "degree" } ] }, "id": { "authority": "EPSG", "code": 4275 } }, "target_crs": { "type": "GeographicCRS", "name": "ETRS89-FRA [RGF93 v2b]", "datum": { "type": "GeodeticReferenceFrame", "name": "Reseau Geodesique Francais 1993 v2b", "anchor_epoch": 2019, "ellipsoid": { "name": "GRS 1980", "semi_major_axis": 6378137, "inverse_flattening": 298.257222101 } }, "coordinate_system": { "subtype": "ellipsoidal", "axis": [ { "name": "Geodetic latitude", "abbreviation": "Lat", "direction": "north", "unit": "degree" }, { "name": "Geodetic longitude", "abbreviation": "Lon", "direction": "east", "unit": "degree" } ] }, "id": { "authority": "EPSG", "code": 9782 }, "remarks": "Replaces ETRS89-FRA [RGF93 v2] (CRS code 9777) from 2021-01-05. See CRS code 9784 for alternate system with axes reversed used by IGN for GIS purposes." }, "interpolation_crs": { "type": "GeographicCRS", "name": "ETRS89-FRA [RGF93 v2b]", "datum": { "type": "GeodeticReferenceFrame", "name": "Reseau Geodesique Francais 1993 v2b", "anchor_epoch": 2019, "ellipsoid": { "name": "GRS 1980", "semi_major_axis": 6378137, "inverse_flattening": 298.257222101 } }, "coordinate_system": { "subtype": "ellipsoidal", "axis": [ { "name": "Geodetic latitude", "abbreviation": "Lat", "direction": "north", "unit": "degree" }, { "name": "Geodetic longitude", "abbreviation": "Lon", "direction": "east", "unit": "degree" } ] }, "id": { "authority": "EPSG", "code": 9782 }, "remarks": "Replaces ETRS89-FRA [RGF93 v2] (CRS code 9777) from 2021-01-05. See CRS code 9784 for alternate system with axes reversed used by IGN for GIS purposes." }, "method": { "name": "Geocentric translations (geog2D domain) by grid (IGN)", "id": { "authority": "EPSG", "code": 1087 } }, "parameters": [ { "name": "Geocentric translation file", "value": "gr3df97a.txt", "id": { "authority": "EPSG", "code": 8727 } } ], "accuracy": "1.0", "scope": "Transformation of coordinates at 1m level of accuracy.", "area": "France - onshore - mainland and Corsica.", "bbox": { "south_latitude": 41.31, "west_longitude": -4.87, "north_latitude": 51.14, "east_longitude": 9.63 }, "id": { "authority": "EPSG", "code": 9889 }, "remarks": "Parameter file is from NTF to ETRS89-FRA [RGF93 v1] (code 9327), assuming that ETRS89-FRA [RGF93 v1] is equivalent to ETRS89-FRA [RGF93 v2b] within the accuracy of the transformation. May be emulated using NTv2 method - see CT code 9891." }
Definition: MapServer - MAPfile
PROJECTION "proj=pipeline" "step" "proj=axisswap" "order=2,1" "step" "proj=unitconvert" "xy_in=deg" "xy_out=rad" "step" "proj=push" "v_3" "step" "proj=cart" "ellps=clrk80ign" "step" "proj=xyzgridshift" "grids=fr_ign_gr3df97a.tif" "grid_ref=output_crs" "ellps=GRS80" "step" "inv" "proj=cart" "ellps=GRS80" "step" "proj=pop" "v_3" "step" "proj=unitconvert" "xy_in=rad" "xy_out=deg" "step" "proj=axisswap" "order=2,1" END
Definition: Mapnik
<?xml version="1.0" encoding="utf-8"?> <Map srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=push +v_3 +step +proj=cart +ellps=clrk80ign +step +proj=xyzgridshift +grids=fr_ign_gr3df97a.tif +grid_ref=output_crs +ellps=GRS80 +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1"> <Layer srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=push +v_3 +step +proj=cart +ellps=clrk80ign +step +proj=xyzgridshift +grids=fr_ign_gr3df97a.tif +grid_ref=output_crs +ellps=GRS80 +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1"> </Layer> </Map>
Definition: SQL (PostGIS)
INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 9889, 'EPSG', 9889, '+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=push +v_3 +step +proj=cart +ellps=clrk80ign +step +proj=xyzgridshift +grids=fr_ign_gr3df97a.tif +grid_ref=output_crs +ellps=GRS80 +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1', 'None');