EPSG:27700

OSGB36 / British National Grid -- United Kingdom Ordnance Survey

Available transformations
to EPSG:4258
EPSG:4258 - ETRS89

Selected transformation

Method: NTv2

Grid Files: OSTN02_NTv2.gsb

Remarks: Approximate alternative to official OSTN02 method (tfm code 7952). Accuracy at 2000 test points compared to OSTN02 (tfm code 1039): latitude 0.5mm av, 17mm max; longitude 0.8mm av, 23mm max. May be taken as approximate CT to WGS 84 - see code 5339.

Information source: Ordnance Survey of Great Britain, http://www.gps.gov.uk

Revision date: 2021-05-13

Attributes

Unit: metre

Geodetic CRS: OSGB36

Datum: Ordnance Survey of Great Britain 1936

Ellipsoid: Airy 1830

Prime meridian: Greenwich

Data source: EPSG

Information source: Ordnance Survey of Great Britain.

Revision date: 2021-03-18

Scope: Engineering survey, topographic mapping.

Area of use: United Kingdom (UK) - offshore to boundary of UKCS within 49°45'N to 61°N and 9°W to 2°E; onshore Great Britain (England, Wales and Scotland). Isle of Man onshore.

Coordinate system: Cartesian 2D CS. Axes: easting, northing (E,N). Orientations: east, north. UoM: m.

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United Kingdom (UK) - Great Britain - England, Scotland and Wales onshore; Isle of Man onshore.
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Definition: OGC Well Known Text 2 (2019)

BOUNDCRS[
    SOURCECRS[
        PROJCRS["OSGB36 / British National Grid",
            BASEGEOGCRS["OSGB36",
                DATUM["Ordnance Survey of Great Britain 1936",
                    ELLIPSOID["Airy 1830",6377563.396,299.3249646,
                        LENGTHUNIT["metre",1]]],
                PRIMEM["Greenwich",0,
                    ANGLEUNIT["degree",0.0174532925199433]],
                ID["EPSG",4277]],
            CONVERSION["British National Grid",
                METHOD["Transverse Mercator",
                    ID["EPSG",9807]],
                PARAMETER["Latitude of natural origin",49,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8801]],
                PARAMETER["Longitude of natural origin",-2,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8802]],
                PARAMETER["Scale factor at natural origin",0.9996012717,
                    SCALEUNIT["unity",1],
                    ID["EPSG",8805]],
                PARAMETER["False easting",400000,
                    LENGTHUNIT["metre",1],
                    ID["EPSG",8806]],
                PARAMETER["False northing",-100000,
                    LENGTHUNIT["metre",1],
                    ID["EPSG",8807]]],
            CS[Cartesian,2],
                AXIS["(E)",east,
                    ORDER[1],
                    LENGTHUNIT["metre",1]],
                AXIS["(N)",north,
                    ORDER[2],
                    LENGTHUNIT["metre",1]],
            USAGE[
                SCOPE["Engineering survey, topographic mapping."],
                AREA["United Kingdom (UK) - offshore to boundary of UKCS within 49°45'N to 61°N and 9°W to 2°E; onshore Great Britain (England, Wales and Scotland). Isle of Man onshore."],
                BBOX[49.75,-9.01,61.01,2.01]],
            ID["EPSG",27700]]],
    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]],
            USAGE[
                SCOPE["Spatial referencing."],
                AREA["Europe - onshore and offshore: Albania; Andorra; Austria; Belgium; Bosnia and Herzegovina; Bulgaria; Croatia; Cyprus; Czechia; Denmark; Estonia; Faroe Islands; Finland; France; Germany; Gibraltar; Greece; Hungary; Ireland; Italy; Kosovo; Latvia; Liechtenstein; Lithuania; Luxembourg; Malta; Moldova; Monaco; Montenegro; Netherlands; North Macedonia; Norway including Svalbard and Jan Mayen; Poland; Portugal; Romania; San Marino; Serbia; Slovakia; Slovenia; Spain; Sweden; Switzerland; United Kingdom (UK) including Channel Islands and Isle of Man; Vatican City State."],
                BBOX[32.88,-16.1,84.73,40.18]],
            ID["EPSG",4258]]],
    ABRIDGEDTRANSFORMATION["OSGB36 to ETRS89 (1)",
        METHOD["NTv2",
            ID["EPSG",9615]],
        PARAMETERFILE["Latitude and longitude difference file","OSTN02_NTv2.gsb"],
        USAGE[
            SCOPE["Transformation of coordinates at 0.03m level of accuracy."],
            AREA["United Kingdom (UK) - Great Britain - England, Scotland and Wales onshore; Isle of Man onshore."],
            BBOX[49.81,-8.69,60.93,1.91]],
        ID["EPSG",5338],
        REMARK["Approximate alternative to official OSTN02 method (tfm code 7952). Accuracy at 2000 test points compared to OSTN02 (tfm code 1039): latitude 0.5mm av, 17mm max; longitude 0.8mm av, 23mm max. May be taken as approximate CT to WGS 84 - see code 5339."]]]

Definition: PROJ.4

+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +ellps=airy +units=m +no_defs +type=crs

Definition: JavaScript (Proj4js) 

proj4.defs("EPSG:27700","+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +ellps=airy +units=m +no_defs +type=crs");

Definition: JSON

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "BoundCRS",
    "source_crs": {
        "type": "ProjectedCRS",
        "name": "OSGB36 / British National Grid",
        "base_crs": {
            "name": "OSGB36",
            "datum": {
                "type": "GeodeticReferenceFrame",
                "name": "Ordnance Survey of Great Britain 1936",
                "ellipsoid": {
                    "name": "Airy 1830",
                    "semi_major_axis": 6377563.396,
                    "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": 4277
            }
        },
        "conversion": {
            "name": "British National Grid",
            "method": {
                "name": "Transverse Mercator",
                "id": {
                    "authority": "EPSG",
                    "code": 9807
                }
            },
            "parameters": [
                {
                    "name": "Latitude of natural origin",
                    "value": 49,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8801
                    }
                },
                {
                    "name": "Longitude of natural origin",
                    "value": -2,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8802
                    }
                },
                {
                    "name": "Scale factor at natural origin",
                    "value": 0.9996012717,
                    "unit": "unity",
                    "id": {
                        "authority": "EPSG",
                        "code": 8805
                    }
                },
                {
                    "name": "False easting",
                    "value": 400000,
                    "unit": "metre",
                    "id": {
                        "authority": "EPSG",
                        "code": 8806
                    }
                },
                {
                    "name": "False northing",
                    "value": -100000,
                    "unit": "metre",
                    "id": {
                        "authority": "EPSG",
                        "code": 8807
                    }
                }
            ]
        },
        "coordinate_system": {
            "subtype": "Cartesian",
            "axis": [
                {
                    "name": "Easting",
                    "abbreviation": "E",
                    "direction": "east",
                    "unit": "metre"
                },
                {
                    "name": "Northing",
                    "abbreviation": "N",
                    "direction": "north",
                    "unit": "metre"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 27700
        }
    },
    "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
        }
    },
    "transformation": {
        "name": "OSGB36 to ETRS89 (1)",
        "method": {
            "name": "NTv2",
            "id": {
                "authority": "EPSG",
                "code": 9615
            }
        },
        "parameters": [
            {
                "name": "Latitude and longitude difference file",
                "value": "OSTN02_NTv2.gsb",
                "id": {
                    "authority": "EPSG",
                    "code": 8656
                }
            }
        ],
        "id": {
            "authority": "EPSG",
            "code": 5338
        }
    }
}

Definition: MapServer - MAPfile

PROJECTION
	"proj=tmerc"
	"lat_0=49"
	"lon_0=-2"
	"k=0.9996012717"
	"x_0=400000"
	"y_0=-100000"
	"ellps=airy"
	"units=m"
	"no_defs"
	"type=crs"
END

Definition: Mapnik

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +ellps=airy +units=m +no_defs +type=crs">
	<Layer srs="+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +ellps=airy +units=m +no_defs +type=crs">
	</Layer>
</Map>