# Set Coordinate System (Geospatial Modeling Wizard)

If there is no projection (.prj) file with the map or you define two fields from a data source as a set of coordinates, you must set the coordinate system.

- Default geographic (longitude and latitude)
- The coordinate system is longitude and latitude.
- Simple Cartesian (X and Y)
- The coordinate system is simple X and Y coordinates.
- Use a Well Known ID (WKID)
- "Well known ID" for common projections.
- Use a Coordinate System Name
- The coordinate system is based on the named projection. The name is enclosed in parentheses.