To Change the Vertical Coordinate System of a GCS

  1. In the Geographic Coordinate System dialog, select the From Library icon.

    The Select Geographic Coordinate System dialog opens.

  2. On the Library tab, expand the folders as needed to locate a GCS that uses a datum of NAD27, NAD83, HPGN, or their equivalent.
  3. Click OK.
  4. In the Geographic Coordinate System dialog, click Details.
    The Geographic Coordinate System Properties dialog opens.
  5. On the Vertical Coordinate System section, in the Name drop-down list, Select the desired vertical coordinate.
    1. Note: Vertical Coordinate Systems will only be listed if they are valid in the same region as the selected Horizontal Coordinate System.
  6. Click OK.

    An alert regarding changes to the Geographic Coordinate Systems will display.

  7. Select the appropriate option for your data, to either reproject or not reproject the data.