Defining a Global Coordinate System
Concept Procedure Quick Reference
 
 
 

To define a coordinate system

  1. Click Map Setup tabCoordinate System panelDefine Global Coordinate System. At the Command prompt, enter ADEDEFCRDSYS.
  2. In the Global Coordinate System Manager dialog box, select a category.
  3. Do one of the following:
    • To create a new coordinate system, click Define.
    • To create a new coordinate system based on an existing, predefined coordinate system, select the coordinate system from the Coordinate Systems In Category list. Click Modify.
  4. On the General tab of the Define Coordinate System dialog box, enter a unique code in the Code box.

    The code must be unique within a category and across all coordinate systems and must not contain spaces. Only the following characters are valid: A-Z (upper or lower case), 0-9, dash, and underscore.

    If you are creating a new coordinate system based on an existing coordinate system, you must change the code before you can change any of the other information.

  5. Enter a description.

    AutoCAD Map 3D displays the description in the Coordinate Systems In Category list of the Global Coordinate System Manager dialog box.

  6. In the Units box, select the units to use for this coordinate system.
  7. Under Coordinate System Type, select one of the following:
    • To base the coordinate system on a datum, select Geodetic. Click Select to specify the datum.
    • To base the coordinate system on an ellipsoid, select Non-Geodetic. Click Select to specify the ellipsoid.
  8. On the Projection tab, select a projection.

    The projection you choose determines how many projection parameters you must enter and the units you can use.

  9. Optionally, under False Origin, enter Northing and Easting values.
  10. Under Projection Parameters, enter values for the remaining fields in the dialog box. Click OK.

    These fields vary according to the projection you select.