EPSG:4279 OS(SN)80
Geographic system in latitude and longitude, in use: Europe - British Isles - UK and Ireland onshore. Datum, ellipsoid and transformation to WGS 84 below.
EPSG publishes no simple transformation to WGS 84 for this datum: conversion works on the ellipsoid alone and can be off by tens of metres.
| Code | EPSG:4279 |
|---|---|
| Name | OS(SN)80 |
| Type | Geographic system |
| Area of use |
Europe - British Isles - UK and Ireland onshore Ireland - onshore. United Kingdom (UK) - onshore - England; Scotland; Wales; Northern Ireland. Isle of Man. |
| Bounds | W -10,56° · S 49,81° · E 1,84° · N 60,90° |
| Countries | Ireland, United Kingdom, Isle of Man |
| Datum | OS (SN) 1980 |
| Ellipsoid | Airy 1830 a = 6377563.396 m · 1/f = 299.3249646 |
| Unit | degree (Lat north, Lon east) |
| Transformation to WGS 84 | No simple transformation published (ellipsoid alone) |
| Scope | Geodesy. |
proj4 definition
+proj=longlat +a=6377563.3959999997 +rf=299.3249646 +no_defsPaste it into QGIS, proj4js, PostGIS (spatial_ref_sys) or GDAL. +towgs84 carries the EPSG transformation to WGS 84; the official code stays EPSG:4279.
WKT (ESRI format, the .prj content)
GEOGCS["GCS_OS_SN_1980",DATUM["D_OS_SN_1980",SPHEROID["Airy_1830",6377563.396,299.3249646]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]]Other systems — Ireland
Source: EPSG registry v11.022 (IOGP), through the PROJ database. Always check a code on epsg.org before contractual work.