Unlike the simple 3- and 7-parameter transformations which are used for many coordinate transformations (see Understanding coordinate conversions, the transformation between New Zealand Geodetic Datum 1949 (NZGD1949) and New Zealand Geodetic Datum 2000 (NZGD2000) requires a distortion grid. This is because distortions, such as deformation, have occurred within the datum.
Understanding coordinate conversions
More information about the distortion grid can be found on NZGD1949 - NZGD2000 Distortion Grid.
Conditions of use
Downloading or using any of our geodetic software applications is taken to be acceptance of the conditions for geodetic downloads listed on the Geodetic software and downloads page.
NZGD1949 and NZGD2000 distortion grid
An ASCII version of the distortion grid can be downloaded as a zip file:
Last updated 20 November 1999
Related information:
LINZS25000 - Standard for New Zealand Geodetic Datum 2000
LINZG25700 Fact sheet - a summary of the key information in LINZS25000
NZGD2000 - NZGD1949 source code on the geodetic software page
NZGD2000 - NZGD1949 source code
This programme provides a conversion between New Zealand Geodetic Datum 2000 (NZGD2000) and New Zealand Geodetic Datum 1949 (NZGD1949) using the NTv2 ASCII distortion grid file. The source code is provided in the C programming language.
Last updated 4 February 2014
To incorporate this source code into custom software, you must use the two files from the zip folder (linzgrid.c and linzgrid.h) and the ASCII version of the distortion grid. More information can be found in the comments of the linzgrid.c file.