rgf93_ntf.gsb
Second step is an emulation (using the NTv2 method) of the geocentric interpolation method described in CT code 9337. Note that the grid file parameters are of opposite sign.
IOGP
2021-09-08
Engineering survey, topographic mapping.
Introduced 1972. Supersedes NTF / Corse (code 27594).
Cartesian 2D CS. Axes: easting, northing (X,Y). Orientations: east, north. UoM: m.
Definition: OGC Well Known Text 2 (2019)
BOUNDCRS[ SOURCECRS[ BOUNDCRS[ SOURCECRS[ PROJCRS["NTF (Paris) / France IV", BASEGEOGCRS["NTF (Paris)", DATUM["Nouvelle Triangulation Francaise (Paris)", ELLIPSOID["Clarke 1880 (IGN)",6378249.2,293.466021293627, LENGTHUNIT["metre",1]]], PRIMEM["Paris",2.5969213, ANGLEUNIT["grad",0.0157079632679489]], ID["EPSG",4807]], CONVERSION["Lambert zone IV", METHOD["Lambert Conic Conformal (1SP)", ID["EPSG",9801]], PARAMETER["Latitude of natural origin",46.85, ANGLEUNIT["grad",0.0157079632679489], ID["EPSG",8801]], PARAMETER["Longitude of natural origin",0, ANGLEUNIT["grad",0.0157079632679489], ID["EPSG",8802]], PARAMETER["Scale factor at natural origin",0.99994471, SCALEUNIT["unity",1], ID["EPSG",8805]], PARAMETER["False easting",234.358, LENGTHUNIT["metre",1], ID["EPSG",8806]], PARAMETER["False northing",4185861.369, LENGTHUNIT["metre",1], ID["EPSG",8807]]], CS[Cartesian,2], AXIS["easting (X)",east, ORDER[1], LENGTHUNIT["metre",1]], AXIS["northing (Y)",north, ORDER[2], LENGTHUNIT["metre",1]], ID["EPSG",27584]]], TARGETCRS[ 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]]], ABRIDGEDTRANSFORMATION["NTF (Paris) to NTF (1)", METHOD["Longitude rotation", ID["EPSG",9601]], PARAMETER["Longitude offset",8414.02501199997, ID["EPSG",8602]], ID["EPSG",1763]]]], TARGETCRS[ GEOGCRS["RGF93 v1", DATUM["Reseau Geodesique Francais 1993 v1", ELLIPSOID["GRS 1980",6378137,298.257222101, 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]], USAGE[ SCOPE["Horizontal component of 3D system."], AREA["France - onshore and offshore, mainland and Corsica (France métropolitaine including Corsica)."], BBOX[41.15,-9.86,51.56,10.38]], ID["EPSG",4171]]], ABRIDGEDTRANSFORMATION["Inverse of RGF93 v1 to NTF (2)", METHOD["Inverse of NTv2", ID["INVERSE(EPSG)",9615]], PARAMETERFILE["Latitude and longitude difference file","rgf93_ntf.gsb"], 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["INVERSE(EPSG)",15958], REMARK["Emulation using NTv2 method of NTF to RGF93 v1 (1), code 9327. Note that grid file parameters are of opposite sign. May be taken as approximate CT to ETRS89 or WGS 84 (see codes 15959 and 15960). Also used to transform later realizations of RGF93 to NTF."]]]
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "BoundCRS", "source_crs": { "type": "BoundCRS", "source_crs": { "type": "ProjectedCRS", "name": "NTF (Paris) / France IV", "base_crs": { "name": "NTF (Paris)", "datum": { "type": "GeodeticReferenceFrame", "name": "Nouvelle Triangulation Francaise (Paris)", "ellipsoid": { "name": "Clarke 1880 (IGN)", "semi_major_axis": 6378249.2, "semi_minor_axis": 6356515 }, "prime_meridian": { "name": "Paris", "longitude": { "value": 2.5969213, "unit": { "type": "AngularUnit", "name": "grad", "conversion_factor": 0.0157079632679489 } } } }, "coordinate_system": { "subtype": "ellipsoidal", "axis": [ { "name": "Geodetic latitude", "abbreviation": "Lat", "direction": "north", "unit": { "type": "AngularUnit", "name": "grad", "conversion_factor": 0.0157079632679489 } }, { "name": "Geodetic longitude", "abbreviation": "Lon", "direction": "east", "unit": { "type": "AngularUnit", "name": "grad", "conversion_factor": 0.0157079632679489 } } ] }, "id": { "authority": "EPSG", "code": 4807 } }, "conversion": { "name": "Lambert zone IV", "method": { "name": "Lambert Conic Conformal (1SP)", "id": { "authority": "EPSG", "code": 9801 } }, "parameters": [ { "name": "Latitude of natural origin", "value": 46.85, "unit": { "type": "AngularUnit", "name": "grad", "conversion_factor": 0.0157079632679489 }, "id": { "authority": "EPSG", "code": 8801 } }, { "name": "Longitude of natural origin", "value": 0, "unit": { "type": "AngularUnit", "name": "grad", "conversion_factor": 0.0157079632679489 }, "id": { "authority": "EPSG", "code": 8802 } }, { "name": "Scale factor at natural origin", "value": 0.99994471, "unit": "unity", "id": { "authority": "EPSG", "code": 8805 } }, { "name": "False easting", "value": 234.358, "unit": "metre", "id": { "authority": "EPSG", "code": 8806 } }, { "name": "False northing", "value": 4185861.369, "unit": "metre", "id": { "authority": "EPSG", "code": 8807 } } ] }, "coordinate_system": { "subtype": "Cartesian", "axis": [ { "name": "Easting", "abbreviation": "X", "direction": "east", "unit": "metre" }, { "name": "Northing", "abbreviation": "Y", "direction": "north", "unit": "metre" } ] }, "id": { "authority": "EPSG", "code": 27584 } }, "target_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 } }, "transformation": { "name": "NTF (Paris) to NTF (1)", "source_crs": { "type": "GeographicCRS", "name": "NTF (Paris) (with Greenwich prime meridian)", "datum": { "type": "GeodeticReferenceFrame", "name": "Nouvelle Triangulation Francaise (Paris) (with Greenwich prime meridian)", "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": { "type": "AngularUnit", "name": "grad", "conversion_factor": 0.0157079632679489 } }, { "name": "Geodetic longitude", "abbreviation": "Lon", "direction": "east", "unit": { "type": "AngularUnit", "name": "grad", "conversion_factor": 0.0157079632679489 } } ] } }, "method": { "name": "Longitude rotation", "id": { "authority": "EPSG", "code": 9601 } }, "parameters": [ { "name": "Longitude offset", "value": 2.5969213, "unit": { "type": "AngularUnit", "name": "grad", "conversion_factor": 0.0157079632679489 }, "id": { "authority": "EPSG", "code": 8602 } } ], "id": { "authority": "EPSG", "code": 1763 } } }, "target_crs": { "type": "GeographicCRS", "name": "RGF93 v1", "datum": { "type": "GeodeticReferenceFrame", "name": "Reseau Geodesique Francais 1993 v1", "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": 4171 } }, "transformation": { "name": "Inverse of RGF93 v1 to NTF (2)", "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 } }, "method": { "name": "Inverse of NTv2", "id": { "authority": "INVERSE(EPSG)", "code": 9615 } }, "parameters": [ { "name": "Latitude and longitude difference file", "value": "rgf93_ntf.gsb", "id": { "authority": "EPSG", "code": 8656 } } ], "id": { "authority": "INVERSE(EPSG)", "code": 15958 } } }
Definition: Mapnik
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