Contrary to previous options in which, by default, the list of elements appears from the EPSG data base, only the list of user transformations is shown. These datum transformations are based on geoid models with their own format. This is why no transformation proposed by OGP is supported on its EPSG data base.

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

 

The Search by section allows the filtering of consultation data by Code and Name. 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, this will show all the datum transformations whose name contains the string entered.

 

 

By double clicking a datum shift on the list its properties are displayed, Information Source, Source Datum , Target Datum  and File.

 

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

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

Transformation Parameters: This allows the selection of the geoid model file on which the datum transformation is based. This file is binary and has the extension *.GDE.