{"$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":"OSGB36 to WGS 84 (9)","method":{"name":"NTv2","id":{"authority":"EPSG","code":9615}},"parameters":[{"name":"Latitude and longitude difference file","value":"OSTN15_NTv2_OSGBtoETRS.gsb","id":{"authority":"EPSG","code":8656}}],"id":{"authority":"EPSG","code":7710}}}