EPSG:29901 OSNI 1952 / Irish National Grid
Projected system (Transverse Mercator) in use: UK - Northern Ireland - onshore. The full definition below, and conversion in one click.
| Code | EPSG:29901 |
|---|---|
| Name | OSNI 1952 / Irish National Grid |
| Type | Projected system — Transverse Mercator |
| Area of use |
UK - Northern Ireland - onshore United Kingdom (UK) - Northern Ireland (Ulster) - onshore. |
| Bounds | W -8,18° · S 53,96° · E -5,34° · N 55,36° |
| Countries | United Kingdom |
| Datum | OSNI 1952 |
| Ellipsoid | Airy 1830 a = 6377563.396 m · 1/f = 299.3249646 |
| Base geographic system | EPSG:4188 — OSNI 1952 |
| Unit | metre (E east, N north) |
| Transformation to WGS 84 | OSNI 1952 to WGS 84 (1) (EPSG:1955) — accuracy 1 m |
| Scope | Engineering survey, topographic mapping. |
Projection parameters
| Parameter | Value | Unit |
|---|---|---|
| Latitude of natural origin | 53.5 | degree |
| Longitude of natural origin | -8 | degree |
| Scale factor at natural origin | 1 | unity |
| False easting | 200000 | metre |
| False northing | 250000 | metre |
proj4 definition
+proj=tmerc +lat_0=53.5 +lon_0=-8 +k=1 +x_0=200000 +y_0=250000 +a=6377563.3959999997 +rf=299.3249646 +units=m +towgs84=482.5,-130.6,564.6,-1.042,-0.214,-0.631,8.15 +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:29901.
WKT (ESRI format, the .prj content)
PROJCS["OSNI_1952_Irish_National_Grid",GEOGCS["GCS_OSNI_1952",DATUM["D_OSNI_1952",SPHEROID["Airy_1830",6377563.396,299.3249646]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",200000.0],PARAMETER["False_Northing",250000.0],PARAMETER["Central_Meridian",-8.0],PARAMETER["Scale_Factor",1.0],PARAMETER["Latitude_Of_Origin",53.5],UNIT["Meter",1.0]]Other systems — United Kingdom
- EPSG:10235OxWo08 Grid
- EPSG:10237SYC20-IRF
- EPSG:10240SYC20 Grid
- EPSG:10272SMITB20-IRF
- EPSG:10275SMITB20 Grid
- EPSG:10277RBEPP12-IRF
- EPSG:10280RBEPP12 Grid
- EPSG:10468COV23-IRF
- EPSG:10471COV23 Grid
- EPSG:10623ECML14-IRF
- EPSG:10626ECML14 Grid
- EPSG:10628WC05-IRF
- EPSG:10632WC05 Grid
- EPSG:20002MWC18 Grid
- EPSG:20033MWC18-IRF
- EPSG:23090ED50 / TM 0 N
- EPSG:27700OSGB36 / British National Grid
- EPSG:29903TM75 / Irish Grid
Source: EPSG registry v11.022 (IOGP), through the PROJ database. Always check a code on epsg.org before contractual work.