Create a spatial reference system (SRS) that uses an existing one as a template on which to base your settings using the Create Spatial Reference System Wizard.
You must have the MANAGE ANY SPATIAL OBJECT or CREATE ANY OBJECT system privilege.
The unit of measure that you want to associate with the SRS must already exist.
When you create a spatial reference system, you use an existing one as a template on which to base your settings. Therefore, choose a spatial reference system that is similar to the one you want to create. Later, you can edit the settings.
The new spatial reference system is added to the database.
This example creates a spatial reference system based on an existing one.
Connect to the database.
In the left pane, right-click.
Select Let Me Choose From The List Of All Predefined Spatial Reference Systems, and then click Next.
The Choose A Spatial Reference System window appears.
To create a spatial reference system based on the NAD83 spatial reference system, type NAD83. As you type a name or ID in the Choose A Predefined Spatial Reference System field, the list of spatial reference systems moves to display the spatial reference system you want to use as a template.
Click NAD83 and then click Next.
The Choose a Line Interpretation window appears.
Click Round Earth to select it as the line interpretation.
Specify NAD83custom in the Name field.
When you create a spatial reference system based on an existing spatial reference system, you set the SRID value to be 1000000000 plus the Well Known value. For example, change the value in the Spatial Reference System ID field from 4269 to 1000004269.
The Specify a Comment window appears.
Optionally, specify a description for the spatial reference system, and then click Next.
The definition for the spatial reference system appears.
You can define the tables that use the spatial reference system.