=== Q: Where can I get the grid shift file needed for apltran for describing the Ordnance Survey National Grid projection? === '''A:'''[[BR]] The NTv2 file describing the OSTN02 transformation can be downloaded from the Ordnance Survey at: https://www.ordnancesurvey.co.uk/business-and-government/help-and-support/navigation-technology/os-net/ostn02-ntv2-format.html This is required if you wish to re-project data into Ordnance Survey National Grid. [wiki:FAQ Back to FAQ]