The OSTN15 is a National Grid Transformation that converts ETRS89 coordinates to OSGB36 coordinates, using a 1 km grid of shifts and a 7-parameter Helmert transformation.
The OSTN15 is a National Grid Transformation that converts ETRS89 coordinates to OSGB36 coordinates, using a 1 km grid of shifts and a 7-parameter Helmert transformation.
OSGB36 is a coordinate system used for mapping in Britain, based on the Airy 1830 ellipsoid and the OSGB36 datum.