EPSG:10991

Xrail84

Attributes

Unit: metre

Geodetic CRS: Xrail84

Datum: Xrail84

Ellipsoid: WGS 84

Prime meridian: Greenwich

Data source: EPSG

Information source: Transport for London, Topographic surveys and mapping Standard S1026, issue A2, March 2016.

Revision date: 2025-10-28

Scope: Engineering survey and topographic mapping for transport applications.

Area of use: United Kingdom (UK) - Greater London and surrounding area.

Coordinate system: Cartesian 3D CS (geocentric). Axes: geocentric X Y Z. Orientations: X and Y in equatorial plane, X positive through intersection with prime meridian, Y through 0°N 90°E. Z axis parallel to mean earth rotation axis and positive towards North Pole. UoM: m.

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SimpleMap

Center coordinates
3974259.67 -18406.32

Projected bounds:
3933906.84 -93179.86
4013388.74 56012.14

WGS84 bounds:
-1.33 51.1
0.8 52.0

United Kingdom (UK) - Greater London and surrounding area.
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Definition: OGC Well Known Text

GEOCCS["Xrail84",
    DATUM["Xrail84",
        SPHEROID["WGS 84",6378137,298.257223563,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","1408"]],
    PRIMEM["Greenwich",0,
        AUTHORITY["EPSG","8901"]],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["Geocentric X",OTHER],
    AXIS["Geocentric Y",OTHER],
    AXIS["Geocentric Z",NORTH],
    AUTHORITY["EPSG","10991"]]

Definition: OGC Well Known Text 2 (2019)

GEODCRS["Xrail84",
    DATUM["Xrail84",
        ELLIPSOID["WGS 84",6378137,298.257223563,
            LENGTHUNIT["metre",1]]],
    PRIMEM["Greenwich",0,
        ANGLEUNIT["degree",0.0174532925199433]],
    CS[Cartesian,3],
        AXIS["(X)",geocentricX,
            ORDER[1],
            LENGTHUNIT["metre",1]],
        AXIS["(Y)",geocentricY,
            ORDER[2],
            LENGTHUNIT["metre",1]],
        AXIS["(Z)",geocentricZ,
            ORDER[3],
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["Engineering survey and topographic mapping for transport applications."],
        AREA["United Kingdom (UK) - Greater London and surrounding area."],
        BBOX[51.1,-1.33,52,0.8]],
    ID["EPSG",10991]]

Definition: PROJ.4

+proj=geocent +ellps=WGS84 +units=m +no_defs +type=crs

Definition: JavaScript (Proj4js) 

proj4.defs("EPSG:10991","+proj=geocent +ellps=WGS84 +units=m +no_defs +type=crs");

Definition: JSON

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "GeodeticCRS",
    "name": "Xrail84",
    "datum": {
        "type": "GeodeticReferenceFrame",
        "name": "Xrail84",
        "ellipsoid": {
            "name": "WGS 84",
            "semi_major_axis": 6378137,
            "inverse_flattening": 298.257223563
        }
    },
    "coordinate_system": {
        "subtype": "Cartesian",
        "axis": [
            {
                "name": "Geocentric X",
                "abbreviation": "X",
                "direction": "geocentricX",
                "unit": "metre"
            },
            {
                "name": "Geocentric Y",
                "abbreviation": "Y",
                "direction": "geocentricY",
                "unit": "metre"
            },
            {
                "name": "Geocentric Z",
                "abbreviation": "Z",
                "direction": "geocentricZ",
                "unit": "metre"
            }
        ]
    },
    "scope": "Engineering survey and topographic mapping for transport applications.",
    "area": "United Kingdom (UK) - Greater London and surrounding area.",
    "bbox": {
        "south_latitude": 51.1,
        "west_longitude": -1.33,
        "north_latitude": 52,
        "east_longitude": 0.8
    },
    "id": {
        "authority": "EPSG",
        "code": 10991
    }
}

Definition: GeoServer

10991=GEOCCS["Xrail84",DATUM["Xrail84",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","1408"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Geocentric X",OTHER],AXIS["Geocentric Y",OTHER],AXIS["Geocentric Z",NORTH],AUTHORITY["EPSG","10991"]]

Definition: MapServer - MAPfile

PROJECTION
	"proj=geocent"
	"ellps=WGS84"
	"units=m"
	"no_defs"
	"type=crs"
END

Definition: Mapnik

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=geocent +ellps=WGS84 +units=m +no_defs +type=crs">
	<Layer srs="+proj=geocent +ellps=WGS84 +units=m +no_defs +type=crs">
	</Layer>
</Map>

Definition: SQL (PostGIS)

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 10991, 'EPSG', 10991, '+proj=geocent +ellps=WGS84 +units=m +no_defs +type=crs', 'GEOCCS["Xrail84",DATUM["Xrail84",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","1408"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Geocentric X",OTHER],AXIS["Geocentric Y",OTHER],AXIS["Geocentric Z",NORTH],AUTHORITY["EPSG","10991"]]');