To create a colored contour map, export it to a KML or KMZ file and open it in Google Earth to see the results:
- Open Surfer.
- Create the map. For example, click Home | New Map | Contour, select Conifer.grd from the Sample files, and click Open.
- If available, the coordinate system information is automatically entered for the Contours layer. In this case, the map is in UTM coordinates.
- KML files convert the coordinates of the map to Lat/Long units, if they are not already Lat/Long, so a coordinate system for the map must be specified. To check this, click Map in the Contents window, and in the Properties window click on the Coordinate System tab.
- If the coordinate system Name is Unreferenced local system, click the Change button, select the coordinate system for the map and click OK.
- Add any color and customizations to the map (see here for instructions).
- In the Contents window, uncheck the check boxes next to Right Axis, Left Axis, Top Axis and Bottom Axis.
Create your map with a specified coordinate system, color and transparency, ready for export to Google Earth.
- Click File | Export.
- Give the file a name, change the Save as type to KML Google Earth KML, and click Save.
- Click OK in the Export Options dialog and the KML file is created.
- Open Google Earth.
- 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.
- The map was exported in page units (inches or centimeters) rather than map units (lat/long, UTM, etc.).
- The map was rotated before exporting.
You can click on the Map in the Contents window and then click on the Coordinate System tab in the Properties window to see if the map has a coordinate system (the Name will show Unreferenced local system if it does not). If the map doesn't have a coordinate system assigned to it, you can follow the instructions here to assign a coordinate system to the map: How Can I Make The Axes Show The Coordinates I Want In Surfer?. If there is no Coordinate System tab, the map likely contains a 3D layer, so it cannot be georeferenced. Contact firstname.lastname@example.org if you wish to add your vote for to our suggestion file for the ability to export a 3D map with georeferencing.
If the Map does have a coordinate system assigned to it, it may be that the map was exported in page units instead of map units. This could happen if there are multiple maps in your SRF file, or if there are drawn objects (points, polygons, polylines, text, color scale or map scale). If either of these cases is applicable, then the default export will be in page units and not map units.
To work around this, choose the map as the scaling source in the export options.
- Click File | Export.
- Change the Save as type to KML Google Earth KML (*.kml) or KMZ Google Earth KMZ (*.kmz), give the file a name and click Save.
- 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).
- Click OK and the KML or KMZ file is created in map units.
For a rotated map, you can remove the rotation and then export the map.
- In the Contents window, click on the Map.
- Click on the View tab in the Properties window.
- If not already set to these values, set the Rotation to 0 and the Tilt to 90.
- 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.
Contact email@example.com if you wish to add your vote to our suggestion file for the ability to export a rotated map with georeferencing.
For more information about exporting Google Earth KML/KMZ files, see the webinar Exporting KML/KMZ files from Surfer for use in Google Earth.