NTv2

The NTv2 National Transformation software can transform coordinates (geographic, UTM or MTM) from one spatial reference system to another using a binary Grid Shift File (.GSB format).  The transformation is 2D (horizontal) therefore heights are not required.  NTv2 is available in an Online version as well as a standalone PC Windows version.  GSD also licenses NTv2 for incorporation in geomatics-related software.

NTv2 Online

  • NTv2 Online can transform coordinates between the NAD27 and NAD83 reference systems only. 
  • File processing accepts GHOST (4 record) format only.
  • Single point input of geographic coordinates must be in Deg Min Sec format.

NTv2 for Windows

A Windows version of NTv2 is now available as a free download from the CSRS database.

  • In File Processing mode: input and output files can be in either GHOST (4 record) or CSV (comma separated values) formats
  • In Single Point Processing mode: geographic coordinates can be entered in either Deg Min Sec, Deg Min or Deg formats
  • The NAD27-NAD83 National Transformation Grid Shift File is included with NTV2 for Windows however other grid shift files can also be used.  Contact your Provincial Survey Agency for Grid Shift Files available for your area. Examples: "NAD83(Original)" to "NAD83CSRS" or "ATS77" to "NAD83CSRS"

GSD will license NTv2 for incorporation as a feature in GIS, cartographic, coordinate computation, and other geomatics-related software products. Inquiries are invited from interested developers.

Distribution is done through FTP site download and the NTv2 package contains:

  • The software: generically written for DOS, the supplied FORTRAN source code can easily be recompiled by the end-user to modify the formats for the input and output coordinate data, or to port the NTv2 to other platforms such as UNIX, VAX/VMS, and MAC/OS.
  • The NAD27-NAD83 National Transformation Grid Shift File
  • Complete Grid Shift File structure specifications and access algorithms to facilitate more complex integration into end-user systems. 
  • User's Guide and Developer's Guide.
  • Two series of digital graphics providing a map-based visual display of the variability of the shifts and their accuracies, and illustrating how well the NTv2 performs at the actual control survey points on which it is based.

To order or for additional information.