Geocentric Datum of Australia - Software

Information about how to perform computations on GDA, together with sample spreadsheets is available from the GDA94 Technical Manual.

Information about how to transform coordinates to and from GDA94 is available from Chapter 7 of the GDA94 Technical Manual V2.4.

ICSM has developed two transformation grids that cover the whole of Australia. One is for transforming AGD66 data, the other for AGD84 data. The grid is available in a Canadian format known as National Transformation version 2 (NTv2). Software packages are available that utilises this grid to create a high accuracy transformation process.

ICSM recommends that:

  • The high accuracy grid based transformation process be used whenever possible, in the interest of ensuring internal and external consistency with other custodians of spatial data.
  • Users independently test software transformation processes to ensure satisfactory results are obtained.

Testing should achieve sub-millimetre performance when forward then back transformations are carried out. Test data sets are available from the GDA94 Technical Manual (Chapter 7, page 28) to assist users perform transformation tests.

The following software supports high accuracy grid based transformation and is freely available:

There are a wide range of companies who market software that can be used for carrying out coordinate transformations. The following list of companies are examples:

*  Supports high accuracy grid base transformation using NTv2 format transformation grid.

**  Not all products support the NTv2 format transformation grid, check with company for details.