What is NTv2?
NTv2 (National Transformation version 2) is a grid of accurate datum shifts in a specific format originally devised by the Geodetic Survey of Canada. Using Australian distortion grids (in NTv2 format), the change in latitude and longitude from AGD to GDA94 can be determined for any position by simple interpolation and is then added to the AGD position to give the GDA94 position. The grid is generally regular, but where necessary may contain “sub-grids’ of greater density to cater for particular areas. A description of the NTv2 algorithm can be found in the manuals for the Victorian GDAit software GDAit (Vic Lands) or GDAit (Melbourne University).
Related Questions
- I have a NTv2 grid file available for which in TRANSDAT no specific reference system is predefined. Can I involve the file in TRANSDAT for exact coordinates transformations?
- Does GeoDLL support highly accurate coordinate transformations with NTv2 grid files?
- How do I perform an NTv2 Transformation on Australian Data in ArcGIS Desktop?
