Emulation of polynomial.
Approximate alternative to official OS polynomial method (tfm code 1041). May be taken as approximate transformation TM75 to WGS 84 - see code 6947.
Ireland - onshore. United Kingdom (UK) - Northern Ireland (Ulster) - onshore.
(0,)
Definition: OGC Well Known Text 2 (2019)
COORDINATEOPERATION["TM75 to ETRS89 (3)", VERSION["OSI-Ire NT approximation"], SOURCECRS[ GEOGCRS["TM75", DATUM["Geodetic Datum of 1965", ELLIPSOID["Airy Modified 1849",6377340.189,299.3249646, 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",4300]]], TARGETCRS[ GEOGCRS["ETRS89", ENSEMBLE["European Terrestrial Reference System 1989 ensemble", MEMBER["European Terrestrial Reference Frame 1989"], MEMBER["European Terrestrial Reference Frame 1990"], MEMBER["European Terrestrial Reference Frame 1991"], MEMBER["European Terrestrial Reference Frame 1992"], MEMBER["European Terrestrial Reference Frame 1993"], MEMBER["European Terrestrial Reference Frame 1994"], MEMBER["European Terrestrial Reference Frame 1996"], MEMBER["European Terrestrial Reference Frame 1997"], MEMBER["European Terrestrial Reference Frame 2000"], MEMBER["European Terrestrial Reference Frame 2005"], MEMBER["European Terrestrial Reference Frame 2014"], ELLIPSOID["GRS 1980",6378137,298.257222101, LENGTHUNIT["metre",1]], ENSEMBLEACCURACY[0.1]], 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",4258]]], METHOD["NTv2", ID["EPSG",9615]], PARAMETERFILE["Latitude and longitude difference file","tm75_etrs89.gsb"], OPERATIONACCURACY[0.41], USAGE[ SCOPE["Emulation of polynomial."], AREA["Ireland - onshore. United Kingdom (UK) - Northern Ireland (Ulster) - onshore."], BBOX[51.39,-10.56,55.43,-5.34]], ID["EPSG",6946], REMARK["Approximate alternative to official OS polynomial method (tfm code 1041). May be taken as approximate transformation TM75 to WGS 84 - see code 6947."]]
Definition: JavaScript (Proj4js)
proj4.defs("EPSG:6946","+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=tm75_etrs89.gsb +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": "TM75 to ETRS89 (3)", "source_crs": { "type": "GeographicCRS", "name": "TM75", "datum": { "type": "GeodeticReferenceFrame", "name": "Geodetic Datum of 1965", "ellipsoid": { "name": "Airy Modified 1849", "semi_major_axis": 6377340.189, "inverse_flattening": 299.3249646 } }, "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": 4300 } }, "target_crs": { "type": "GeographicCRS", "name": "ETRS89", "datum_ensemble": { "name": "European Terrestrial Reference System 1989 ensemble", "members": [ { "name": "European Terrestrial Reference Frame 1989", "id": { "authority": "EPSG", "code": 1178 } }, { "name": "European Terrestrial Reference Frame 1990", "id": { "authority": "EPSG", "code": 1179 } }, { "name": "European Terrestrial Reference Frame 1991", "id": { "authority": "EPSG", "code": 1180 } }, { "name": "European Terrestrial Reference Frame 1992", "id": { "authority": "EPSG", "code": 1181 } }, { "name": "European Terrestrial Reference Frame 1993", "id": { "authority": "EPSG", "code": 1182 } }, { "name": "European Terrestrial Reference Frame 1994", "id": { "authority": "EPSG", "code": 1183 } }, { "name": "European Terrestrial Reference Frame 1996", "id": { "authority": "EPSG", "code": 1184 } }, { "name": "European Terrestrial Reference Frame 1997", "id": { "authority": "EPSG", "code": 1185 } }, { "name": "European Terrestrial Reference Frame 2000", "id": { "authority": "EPSG", "code": 1186 } }, { "name": "European Terrestrial Reference Frame 2005", "id": { "authority": "EPSG", "code": 1204 } }, { "name": "European Terrestrial Reference Frame 2014", "id": { "authority": "EPSG", "code": 1206 } } ], "ellipsoid": { "name": "GRS 1980", "semi_major_axis": 6378137, "inverse_flattening": 298.257222101 }, "accuracy": "0.1", "id": { "authority": "EPSG", "code": 6258 } }, "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": 4258 } }, "method": { "name": "NTv2", "id": { "authority": "EPSG", "code": 9615 } }, "parameters": [ { "name": "Latitude and longitude difference file", "value": "tm75_etrs89.gsb", "id": { "authority": "EPSG", "code": 8656 } } ], "accuracy": "0.41", "scope": "Emulation of polynomial.", "area": "Ireland - onshore. United Kingdom (UK) - Northern Ireland (Ulster) - onshore.", "bbox": { "south_latitude": 51.39, "west_longitude": -10.56, "north_latitude": 55.43, "east_longitude": -5.34 }, "id": { "authority": "EPSG", "code": 6946 }, "remarks": "Approximate alternative to official OS polynomial method (tfm code 1041). May be taken as approximate transformation TM75 to WGS 84 - see code 6947." }
Definition: MapServer - MAPfile
PROJECTION "proj=pipeline" "step" "proj=axisswap" "order=2,1" "step" "proj=unitconvert" "xy_in=deg" "xy_out=rad" "step" "proj=hgridshift" "grids=tm75_etrs89.gsb" "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=hgridshift +grids=tm75_etrs89.gsb +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=hgridshift +grids=tm75_etrs89.gsb +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 ( 6946, 'EPSG', 6946, '+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +proj=hgridshift +grids=tm75_etrs89.gsb +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1', 'None');