Ellipsoid: Airy 1830
Prime meridian: Greenwich
Data source: EPSG
Information source: Ordnance Survey of Great Britain.
Revision date: 2022-03-23
Scope: Topographic mapping.
Remarks: The average accuracy of OSTN compared to the old triangulation network (down to 3rd order) is 0.1m. With the introduction of OSTN15, the area for OGSB36 has effectively been extended from Britain to cover the adjacent UK Continental Shelf.
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json", "type": "GeodeticReferenceFrame", "name": "Ordnance Survey of Great Britain 1936", "ellipsoid": { "name": "Airy 1830", "semi_major_axis": 6377563.396, "inverse_flattening": 299.3249646 }, "scope": "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": { "south_latitude": 49.75, "west_longitude": -9.01, "north_latitude": 61.01, "east_longitude": 2.01 }, "id": { "authority": "EPSG", "code": 6277 } }