How To: Unproject shapefiles from UTM NAD 83 to GCS NAD 83 (Decimal Degrees)


This example shows how to use the Projection Utility to unproject shapefiles from UTM Zone 11 NAD 83 Meters to GCS (Geographic Coordinate System) NAD 83 Decimal Degrees.


Example projection parameters

Projection Name: NAD_1983_UTM_Zone11N
Units: Meters
Projection: UTM
Geographic Coordinate System: NAD 1983
Zone: 11 North

Projection Name: GCS_North_American_1983
Units: Degrees
Projection: None (Geographic Coordinate System)
Datum: NAD 1983

  1. Load the shapefile and initialize the Projection Utility.
    A. Start ArcView.
    B. Select File > Extensions.
    C. Check 'Projection Utility Wizard' and click OK.
    D. Create a new view and add the shapefile to be projected.
    E. Select File > ArcView Projection Utility.

    The shapefile should be listed in the 'Step 1' dialog box.
    [O-Image] Projection Utility - Step1 dialog box
    If the Coordinate System in the 'Step 1' dialog box shows 'unkown,' you need to define the input projection parameters as shown below. If the content of that field is other than 'unknown,' you can skip the input projection parameters definition.
  2. Click Next on the 'Step 1' dialog box.
  3. Define the input projection parameters. For our example, use the parameters shown above.
    A. Set Coordinate System Type to Projected.
    B. Set the Name for your projection.
    C. Set the Units for your projection.

    [O-Image] Projection Utility - Step 2 dialog box
  4. Click Next on the 'Step 2' dialog box. Click Yes if you are prompted to save the coordinate system.
  5. Define the output projection parameters. For example, use the output parameters shown above.
    A. Set Coordinate System Type to Geographic.
    B. Set the Name for the coordinate system.
    C. Set the Units for the coordinate system.

    [O-Image] Projection Utility - Step 3 dialog box
  6. Click Next on the 'Step 3' dialog box.
  7. Click Browse to specify a name and location for the new shapefile.
  8. Click Next on the 'Step 4' dialog box.
  9. Review the Summary of the projection parameters.
  10. Click Finish.

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