This shows the list of transformations included on the EPSG data base whose target reference system is WGS 84 or ETRS 89.

Each line of the list gathers the code and the name of the datum shift separated by two points.

 

 

The drop down list of the section Data Source allows EPSG data consultation to be switched to user data and vice versa.

 

 

The Search By section allows the filtering of consultation data by Code, Name and Area. This latter option is only available for EPSG data. The zone name (continent, country etc) must be specified in English. The string to be searched must be entered in the box on the right and the  button pressed. If searching by code, this will only show the result if this same code can be found on the data base, whilst in the search by name and area, this will show all the datum transformations whose name or usage area contains the string entered.

 

 

By double clicking on a datum transformation from the list its properties are displayed, Information Source, Source Datum, Target Datum, Transformation Parameters, Area of Use, Revision Data and Remarks.

 

 

It allows the creation of new user datum shift. The data requested are:

 

 

Code: An alphanumeric string of up to 16 characters is allowed.

Name: An alphanumeric string of up to 64 characters is allowed.

Information Source: Optional field. An alphanumeric string of up to 128 characters is allowed.

Source Datum: It must be selected from the list shown by pressing the  button.

Target Datum: The datum WGS 84 (code EPSG 6326) is established by default.

Transformation Parameters: By pressing this button the screen is shown where the transformation parameters are entered. 3 datum transformation types are presented: 3 Parameters at WGS-84, 7 Parameters  at WGS-84 and NTv2 Grid.

 

The parameters requested for each transformation type are:

3 Parameters at WGS-84

            dX: Displacement X in metres.

dY: Displacement Y in metres.

dZ: Displacement Z in metres.

 

7 Parameters at WGS-84

            dX: Displacement X in metres.

dY: Displacement Y in metres.

dZ: Displacement Z in metres.

       dX: Rotation X in arc seconds.

dY: Rotation Y in arc seconds.

dZ: Rotation Z in arc seconds.

dS: Scale in parts per million (ppm)

 

NTv2 Grid

File containing the data transformation mesh with the format proposed by Geodetic Survey of Canada, version 2. This file has the extension *.GSB and it must be selected by pressing the  button.