Unit: metre
Data source: EPSG
Information source: Ordnance Survey of Great Britain.
Revision date: 2006-11-27
Remarks: Original definition is a=20923713, b=20853810 feet of 1796. 1/f is given to 7 decimal places. For the 1936 retriangulation OSGB defines the relationship of 10 feet of 1796 to the International metre through ([10^0.48401603]/10) exactly = 0.3048007491...
Definition: OGC Well Known Text
SPHEROID["Airy 1830",6377563.396,299.3249646, AUTHORITY["EPSG","7001"]]
Definition: OGC Well Known Text 2 (2019)
ELLIPSOID["Airy 1830",6377563.396,299.3249646, LENGTHUNIT["metre",1], ID["EPSG",7001]]
Definition: ESRI Well Known Text
SPHEROID["Airy_1830",6377563.396,299.3249646]
Definition: JSON
{ "$schema": "https://proj.org/schemas/v0.5/projjson.schema.json", "type": "Ellipsoid", "name": "Airy 1830", "semi_major_axis": 6377563.396, "inverse_flattening": 299.3249646, "id": { "authority": "EPSG", "code": 7001 } }