Today sees the official launch of Ordnance Survey’s new geoid model OSGM15. This is to replace their previous model OSGM02 that has been the cornerstone of the British National Grid coordinate system since 2002. The new model is both a refinement of the accuracy and an increase in the model’s extent to cover offshore bathymetry.
As a consequence it will now be used to refine the definition of the British National Grid, the Irish Grid and the Irish Transverse Mercator map projections. To accompany this Ordnance Survey, along with Ordnance Survey Ireland and the Land and Property Services of Northern Ireland, commissioned me to re-write their popular Grid InQuest software to serve as a reference implementation for this new system.
The new software is written in Free Pascal and there are binaries available for Linux, Windows and Mac OSX. Moreover, the software is released under an open source licence so the entire project repository is available on Bitbucket here:
If any one is interested in more details about what the software can do a digital manual is also available for download here:
Further technical data concerning the definition of OSGM15 can be found here: