Defining an Ellipsoid
Concept Procedure Quick Reference

To define an ellipsoid

  1. Do one of the following:
    • On the General tab of the Define Datum dialog box or the Modify Datum dialog box, under Ellipsoid, click Define.

      Click Map Setup tabCoordinate System panelDefine Global Coordinate System. At the Command prompt, enter ADEDEFCRDSYS. Select Define or Modify.

    • Under Coordinate System Type on the General tab of the Define Global Coordinate System dialog box, select Non-Geodetic. Click Define.
  2. In the Ellipsoid Manager dialog box, click Define.
  3. In the Define Ellipsoid dialog box, enter a code and description for the ellipsoid.

    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.

    AutoCAD Map 3D displays the description in the Available Ellipsoids list.

  4. Under Ellipsoid Dimensions, do the following:
  5. Select a calculation method.
  6. Enter values for the two parameters that correspond to the calculation method you chose. AutoCAD Map 3D computes the other two values based on the ones you enter.
  7. Click OK.