User Tools

Site Tools


This is an old revision of the document!

Grid Shifts Files

Documentation | Other Specifications | Grid Shifts Files

Coordinate transformation engine can perform transformations using grid shift files.

Supported formats

  • NTv2 (.gsb)
    Standard file supported across many countries. Also includes information that is not in use (quality). Therefore converting to .ttkgs file is recommended.
  • NADCON files (.las, *.los, *.gtx)
    Not supported. Should be first converted to supported formats.
  • TatukGIS Grid Shift (.ttkgs)
    Minimized grids shift file format. Only for files deployed by TatukGIS.

How to deploy

  • Grid shit files are pretty big. Therefore deploying all possible files is not a recommended option.
  • Copy desired files into application folder on Datums subfolder of an application folder.
  • To provide general support for USA & Canada NAD27 deploy files:
    • conus
    • alaska
    • hawaii
    • prvi
    • stgeorge
    • stlrnc
    • stpaul
    • NTV2_0

Order of interpretation

A program will try to localize grid shift file in this order:

  1. File .gsb in application folder
  2. File .gsb in Datums subfolder,
  3. File .gsb in a folder specified by TGIS_CSTransformGridShift.Folder metadata.
  4. File .ttkgs files in application.
  5. File .ttkgs in Datums subfolder,
  6. File .ttkgs in a folder specified by TGIS_CSTransformGridShift.Folder metadata.

So in short:

  1. File .gsb is more important then .ttkgs.
  2. File located in application folder is more important then file in other location.

How to obtain grid shift files

We collect some common files for you. Files are installed in a deployment Grid Shift Files folder. The readme.txt file installed in the deployment folder contains information about grid shift files we were not able to provide or we even don't know where to find.

2018/12/19 10:12