EPSG:11390

OSGB36 / Heathrow Airport GIS Grid 2026

Transform Get position on a map

Available transformations
to EPSG:4326
EPSG:4326 - WGS 84

Selected transformation

Name: OSGB36 to WGS 84 (2)

Method: Geocentric translations (geog2D domain)

Remarks: Derived at 24 stations. Accuracy 5m, 5m and 6m in X, Y and Z axes.

Information source: U.S. Defense Mapping Agency TR8350.2 September 1987.

Revision date: 2021-03-18

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 on behalf of ESRI (UK).

Revision date: 2026-03-05

Scope: GIS.

Remarks: Heathrow Airport GIS Grid 2026 approximates Heathrow Airport Grid (HAG) (CRS code 11378) to an accuracy of better than 12mm within airport area and 89 mm across full area of use (2D RMS 0.007 and 0.039 m respectively derived through comparison of coordinates at 100m spacing throughout the airport area). Created for use in GIS applications that do not support the true HAG definition through engineering CRS (code 11378) and similarity transformation to British National Grid (code 11388). Accuracy of approximation deteriorates beyond airport extent - do not use this CRS beyond that area.

Area of use: UK - Heathrow airport and surrounding area.

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

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SimpleMap

Center coordinates
-118336.62 159165.6

Projected bounds:
-427964.16 -179136.91
171397.2 510181.69

WGS84 bounds:
-6.5 49.81
1.84 55.85

United Kingdom (UK) - England onshore.
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Definition: OGC Well Known Text

PROJCS["OSGB36 / Heathrow Airport GIS Grid 2026",
    GEOGCS["OSGB36",
        DATUM["Ordnance_Survey_of_Great_Britain_1936",
            SPHEROID["Airy 1830",6377563.396,299.3249646],
            TOWGS84[371,-112,434,0,0,0,0]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4277"]],
    PROJECTION["Local Orthographic"],
    PARAMETER["latitude_of_center",51.4701102238889],
    PARAMETER["longitude_of_center",-0.451656585555556],
    PARAMETER["azimuth",359.700932272222],
    PARAMETER["scale_factor",1.000002816],
    PARAMETER["false_easting",7334.818],
    PARAMETER["false_northing",5637.421],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["Easting",EAST],
    AXIS["Northing",NORTH],
    AUTHORITY["EPSG","11390"]]

Definition: OGC Well Known Text 2 (2019)

BOUNDCRS[
    SOURCECRS[
        PROJCRS["OSGB36 / Heathrow Airport GIS Grid 2026",
            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["Heathrow Airport GIS Grid 2026",
                METHOD["Local Orthographic",
                    ID["EPSG",1130]],
                PARAMETER["Latitude of projection centre",51.4701102238889,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8811]],
                PARAMETER["Longitude of projection centre",-0.451656585555556,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8812]],
                PARAMETER["Azimuth at projection centre",359.700932272222,
                    ANGLEUNIT["degree",0.0174532925199433],
                    ID["EPSG",8813]],
                PARAMETER["Scale factor at projection centre",1.000002816,
                    SCALEUNIT["unity",1],
                    ID["EPSG",8815]],
                PARAMETER["Easting at projection centre",7334.818,
                    LENGTHUNIT["metre",1],
                    ID["EPSG",8816]],
                PARAMETER["Northing at projection centre",5637.421,
                    LENGTHUNIT["metre",1],
                    ID["EPSG",8817]]],
            CS[Cartesian,2],
                AXIS["(E)",east,
                    ORDER[1],
                    LENGTHUNIT["metre",1]],
                AXIS["(N)",north,
                    ORDER[2],
                    LENGTHUNIT["metre",1]],
            USAGE[
                SCOPE["GIS."],
                AREA["UK - Heathrow airport and surrounding area."],
                BBOX[51.42,-0.56,51.52,-0.37]],
            ID["EPSG",11390]]],
    TARGETCRS[
        GEOGCRS["WGS 84",
            ENSEMBLE["World Geodetic System 1984 ensemble",
                MEMBER["World Geodetic System 1984 (Transit)"],
                MEMBER["World Geodetic System 1984 (G730)"],
                MEMBER["World Geodetic System 1984 (G873)"],
                MEMBER["World Geodetic System 1984 (G1150)"],
                MEMBER["World Geodetic System 1984 (G1674)"],
                MEMBER["World Geodetic System 1984 (G1762)"],
                MEMBER["World Geodetic System 1984 (G2139)"],
                MEMBER["World Geodetic System 1984 (G2296)"],
                ELLIPSOID["WGS 84",6378137,298.257223563,
                    LENGTHUNIT["metre",1]],
                ENSEMBLEACCURACY[2.0]],
            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["World."],
                BBOX[-90,-180,90,180]],
            ID["EPSG",4326]]],
    ABRIDGEDTRANSFORMATION["Transformation from unknown to WGS84",
        METHOD["Position Vector transformation (geog2D domain)",
            ID["EPSG",9606]],
        PARAMETER["X-axis translation",371,
            ID["EPSG",8605]],
        PARAMETER["Y-axis translation",-112,
            ID["EPSG",8606]],
        PARAMETER["Z-axis translation",434,
            ID["EPSG",8607]],
        PARAMETER["X-axis rotation",0,
            ID["EPSG",8608]],
        PARAMETER["Y-axis rotation",0,
            ID["EPSG",8609]],
        PARAMETER["Z-axis rotation",0,
            ID["EPSG",8610]],
        PARAMETER["Scale difference",1,
            ID["EPSG",8611]]]]

Definition: ESRI Well Known Text

PROJCS["OSGB36_Heathrow_Airport_GIS_Grid_2026",
    GEOGCS["GCS_OSGB_1936",
        DATUM["D_OSGB_1936",
            SPHEROID["Airy_1830",6377563.396,299.3249646]],
        PRIMEM["Greenwich",0.0],
        UNIT["Degree",0.0174532925199433]],
    PROJECTION["Local"],
    PARAMETER["False_Easting",7334.818],
    PARAMETER["False_Northing",5637.421],
    PARAMETER["Scale_Factor",1.000002816],
    PARAMETER["Azimuth",-0.299067727777981],
    PARAMETER["Longitude_Of_Center",-0.451656585555556],
    PARAMETER["Latitude_Of_Center",51.4701102238889],
    UNIT["Meter",1.0]]

Definition: PROJ.4

+proj=ortho +lat_0=51.4701102238889 +lon_0=-0.451656585555556 +alpha=359.700932272222 +k=1.000002816 +x_0=7334.818 +y_0=5637.421 +ellps=airy +towgs84=371,-112,434,0,0,0,0 +units=m +no_defs +type=crs

Definition: JavaScript (Proj4js) 

proj4.defs("EPSG:11390","+proj=ortho +lat_0=51.4701102238889 +lon_0=-0.451656585555556 +alpha=359.700932272222 +k=1.000002816 +x_0=7334.818 +y_0=5637.421 +ellps=airy +towgs84=371,-112,434,0,0,0,0 +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 / Heathrow Airport GIS Grid 2026",
        "base_crs": {
            "type": "GeographicCRS",
            "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": "Heathrow Airport GIS Grid 2026",
            "method": {
                "name": "Local Orthographic",
                "id": {
                    "authority": "EPSG",
                    "code": 1130
                }
            },
            "parameters": [
                {
                    "name": "Latitude of projection centre",
                    "value": 51.4701102238889,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8811
                    }
                },
                {
                    "name": "Longitude of projection centre",
                    "value": -0.451656585555556,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8812
                    }
                },
                {
                    "name": "Azimuth at projection centre",
                    "value": 359.700932272222,
                    "unit": "degree",
                    "id": {
                        "authority": "EPSG",
                        "code": 8813
                    }
                },
                {
                    "name": "Scale factor at projection centre",
                    "value": 1.000002816,
                    "unit": "unity",
                    "id": {
                        "authority": "EPSG",
                        "code": 8815
                    }
                },
                {
                    "name": "Easting at projection centre",
                    "value": 7334.818,
                    "unit": "metre",
                    "id": {
                        "authority": "EPSG",
                        "code": 8816
                    }
                },
                {
                    "name": "Northing at projection centre",
                    "value": 5637.421,
                    "unit": "metre",
                    "id": {
                        "authority": "EPSG",
                        "code": 8817
                    }
                }
            ]
        },
        "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": 11390
        }
    },
    "target_crs": {
        "type": "GeographicCRS",
        "name": "WGS 84",
        "datum_ensemble": {
            "name": "World Geodetic System 1984 ensemble",
            "members": [
                {
                    "name": "World Geodetic System 1984 (Transit)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1166
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G730)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1152
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G873)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1153
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G1150)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1154
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G1674)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1155
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G1762)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1156
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G2139)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1309
                    }
                },
                {
                    "name": "World Geodetic System 1984 (G2296)",
                    "id": {
                        "authority": "EPSG",
                        "code": 1383
                    }
                }
            ],
            "ellipsoid": {
                "name": "WGS 84",
                "semi_major_axis": 6378137,
                "inverse_flattening": 298.257223563
            },
            "accuracy": "2.0",
            "id": {
                "authority": "EPSG",
                "code": 6326
            }
        },
        "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": 4326
        }
    },
    "transformation": {
        "name": "Transformation from unknown to WGS84",
        "method": {
            "name": "Position Vector transformation (geog2D domain)",
            "id": {
                "authority": "EPSG",
                "code": 9606
            }
        },
        "parameters": [
            {
                "name": "X-axis translation",
                "value": 371,
                "unit": "metre",
                "id": {
                    "authority": "EPSG",
                    "code": 8605
                }
            },
            {
                "name": "Y-axis translation",
                "value": -112,
                "unit": "metre",
                "id": {
                    "authority": "EPSG",
                    "code": 8606
                }
            },
            {
                "name": "Z-axis translation",
                "value": 434,
                "unit": "metre",
                "id": {
                    "authority": "EPSG",
                    "code": 8607
                }
            },
            {
                "name": "X-axis rotation",
                "value": 0,
                "unit": {
                    "type": "AngularUnit",
                    "name": "arc-second",
                    "conversion_factor": 4.84813681109536e-06
                },
                "id": {
                    "authority": "EPSG",
                    "code": 8608
                }
            },
            {
                "name": "Y-axis rotation",
                "value": 0,
                "unit": {
                    "type": "AngularUnit",
                    "name": "arc-second",
                    "conversion_factor": 4.84813681109536e-06
                },
                "id": {
                    "authority": "EPSG",
                    "code": 8609
                }
            },
            {
                "name": "Z-axis rotation",
                "value": 0,
                "unit": {
                    "type": "AngularUnit",
                    "name": "arc-second",
                    "conversion_factor": 4.84813681109536e-06
                },
                "id": {
                    "authority": "EPSG",
                    "code": 8610
                }
            },
            {
                "name": "Scale difference",
                "value": 0,
                "unit": {
                    "type": "ScaleUnit",
                    "name": "parts per million",
                    "conversion_factor": 1e-06
                },
                "id": {
                    "authority": "EPSG",
                    "code": 8611
                }
            }
        ]
    }
}

Definition: GeoServer

11390=PROJCS["OSGB36 / Heathrow Airport GIS Grid 2026",GEOGCS["OSGB36",DATUM["Ordnance_Survey_of_Great_Britain_1936",SPHEROID["Airy 1830",6377563.396,299.3249646],TOWGS84[371,-112,434,0,0,0,0]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4277"]],PROJECTION["Local Orthographic"],PARAMETER["latitude_of_center",51.4701102238889],PARAMETER["longitude_of_center",-0.451656585555556],PARAMETER["azimuth",359.700932272222],PARAMETER["scale_factor",1.000002816],PARAMETER["false_easting",7334.818],PARAMETER["false_northing",5637.421],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","11390"]]

Definition: MapServer - MAPfile

PROJECTION
	"proj=ortho"
	"lat_0=51.4701102238889"
	"lon_0=-0.451656585555556"
	"alpha=359.700932272222"
	"k=1.000002816"
	"x_0=7334.818"
	"y_0=5637.421"
	"ellps=airy"
	"towgs84=371,-112,434,0,0,0,0"
	"units=m"
	"no_defs"
	"type=crs"
END

Definition: Mapnik

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=ortho +lat_0=51.4701102238889 +lon_0=-0.451656585555556 +alpha=359.700932272222 +k=1.000002816 +x_0=7334.818 +y_0=5637.421 +ellps=airy +towgs84=371,-112,434,0,0,0,0 +units=m +no_defs +type=crs">
	<Layer srs="+proj=ortho +lat_0=51.4701102238889 +lon_0=-0.451656585555556 +alpha=359.700932272222 +k=1.000002816 +x_0=7334.818 +y_0=5637.421 +ellps=airy +towgs84=371,-112,434,0,0,0,0 +units=m +no_defs +type=crs">
	</Layer>
</Map>

Definition: SQL (PostGIS)

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 11390, 'EPSG', 11390, '+proj=ortho +lat_0=51.4701102238889 +lon_0=-0.451656585555556 +alpha=359.700932272222 +k=1.000002816 +x_0=7334.818 +y_0=5637.421 +ellps=airy +towgs84=371,-112,434,0,0,0,0 +units=m +no_defs +type=crs', 'PROJCS["OSGB36 / Heathrow Airport GIS Grid 2026",GEOGCS["OSGB36",DATUM["Ordnance_Survey_of_Great_Britain_1936",SPHEROID["Airy 1830",6377563.396,299.3249646],TOWGS84[371,-112,434,0,0,0,0]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4277"]],PROJECTION["Local Orthographic"],PARAMETER["latitude_of_center",51.4701102238889],PARAMETER["longitude_of_center",-0.451656585555556],PARAMETER["azimuth",359.700932272222],PARAMETER["scale_factor",1.000002816],PARAMETER["false_easting",7334.818],PARAMETER["false_northing",5637.421],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","11390"]]');