British National Grid Projection Support

The British National Grid is based on the Transverse Mercator projection. TerrSet does support this projection, but a georeference file (.ref) will need to be created with the correct parameters.

Create a .ref file that has that projection, assuming the Airy ellipsoid and OSGB 1936 Datum. The Molodensky constants (DX, DY, DZ) for this Datum/Ellipsoid pair can be found in our Manual, Appendix 2. Just select the correct location for the area you are covering and specify the correct constants.

There is more information in the Help on creating the .ref files and under the Help for the PROJECT module.

A sample georeference file (.ref) is below and attached that can be adapted for your specific location.


ref. system : BNG-OSGB 1936
projection : Transverse Mercator
datum : OSGB 1936
delta WGS84 : 371 -112 434
ellipsoid : Airy
major S-ax : 6377563.396
minor S-ax : 6356256.909
origin Long : -2
origin Lat : 49
origin X : 400000
origin Y : -100000
scale Fac : 0.9996012717
units : meters
parameters : 0

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