ETRS89 to EWR3-IRF (1)
EPSG:10850±0 m- Method:
- NTv2
- Area of use:
- UK - Oxford to Cambridge
- Scope:
- Engineering survey and topographic mapping for railway applications.
Grid file: TN15-ETRS89-to-EWR3-IRF.gsb
In conjunction with the EWR3-TM map projection (code 9765) applied to EWR3-IRF (code 10849), emulates the EWR3 Snake projection. Applied to ETRS89 (as realized through the OSNet v2009 CORS) defines EWR3-IRF hence is errorless. In 2024 the EWR2 Grid (ETRS89 / EWR2 SnakeGrid) was extended eastwards as the EWR3 Grid (ETRS89 / EWR3 SnakeGrid). To the west of Bedford the EWR2 Grid is an exact subset of the EWR3 Grid; over this extent the EWR3 Grid replaces the EWR2 Grid. The EWR2 emulation file TN15-ETRS89-to-EWR2-IRF.gsb (CT code 9764) is a subset of this EWR3 emulation file TN15-ETRS89-to-EWR3-IRF.gsb; west of Bedford the content of the two files is identical.