Display contours from Surfer in Google Earth

Google Earth is a universally known and easily accessible tool for sharing results with clients or for taking your maps into the field.  With Surfer, you can easily export maps to KML or KMZ format to display them in Google Earth.

Set the Map Coordinate System

Before exporting your map to Google Earth you must first ensure the map has a coordinate system assigned in Surfer.  This allows Surfer to create the KMZ/KML with the proper coordinates for display in Google Earth.

1. Click the Map in the Contents window to select it.
   If available, the coordinate system information is automatically read and assigned for each layer in the map upon creation.  The Map coordinate system will be assigned to the same coordinate system as the first map layer.
2. Click the Coordinate System tab in the Properties window.
   If the coordinate system Name is Unreferenced local system, this indicates that the first map layer did not have a known coordinate system assigned.  To assign the same coordinate system to the Map and each unreferenced layer:
3. Click the Change button in the Coordinate system field.
4. In the Assign Coordinate System dialog, select the coordinate system for the map and click OK. 
   Note: in this case the coordinate system for the map should be the system used to gather the data or create the source grid file.
5. Click Assign Now in the Assign to unreferenced layers field. 
   Both your map and any unreferenced layers now share the same coordinate system assignment in Surfer.  If desired, you can now change the target coordinate system for the map to any desired system and Surfer will convert the map on the fly.

Verify your map has a Coordinate System assigned in Surfer before exporting to Google Earth.

Export your Surfer map to Google Earth

1. Click File | Export.
2. In the Export dialog, change the Save as type to KML  Google Earth KML, enter a File name and click Save.
3. Click OK in the Export Options dialog and the KML file is created.
   Note: To export the map without the axes you can uncheck them in the Contents window prior to export or select the map layer you'd like to export and choose to export selected objects only.

View your Surfer map in Google Earth

1. Open Google Earth.
2. Click File | Open, select the KML file, and click Open. The contour map is loaded and displayed over the aerial photo. The color and transparency properties are retained.

Open the KML file in Google Earth and the map is automatically placed in the correct location over the aerial image.

If your KML or KMZ file ends up in the wrong location

There are three possible reasons why the KML or KMZ file exported from Surfer ends up where it is not supposed to:

• The map doesn't have a coordinate system assigned to it.
  If your map contains a 3D surface map or a 3D wireframe, it is not possible to assign a coordinate system or export the map to Google Earth. Contact support@goldensoftware.com if you would benefit from coordinate system support for these map types.
  
  
• The map was exported in page units (inches or centimeters) rather than map units (lat/long, UTM, etc.).
  Surfer defaults to exporting in page units when there are multiple Mapframes in the same Plot document and sometimes when there are objects drawn on the page that are not linked to a map. To ensure your map was exported in map units:
  1. Click File | Export.
  2. In the Export dialog, change the Save as type to KML Google Earth KML (*.kml) or KMZ Google Earth KMZ (*.kmz), enter the File name and click Save.
  3. In the Export Options dialog, on the Scaling page, set the Scaling source to your Map. This updates the File Rectangle coordinates to be in the units of the map (and different from the Source Rectangle coordinates).
  4. Click OK and the KML or KMZ file is created in map units.
• The map was rotated before exporting.
  All Surfer maps with any rotation or sheer applied are exported in page units. Contact support@goldensoftware.com if you would benefit from the ability to export a rotated map with georeferencing. 
  To remove the rotation and then export the map:
  1. In the Contents window, click on the Map.
  2. Click on the View tab in the Properties window.
  3. If not already set to these values, set the Rotation to 0 and the Tilt to 90.
  4. If Rotation and Tilt are already 0 and 90 respectively, click Home | Selection | Transform, set the Rotation to 0 in the Transform dialog, and click OK.

For more information about exporting Google Earth KML/KMZ files, see the webinar Bring Your Data to Life with Google Earth and Surfer.