Working in Google EarthTM is becoming an increasingly popular method for sharing and displaying maps among colleagues and between consultants and clients. It is a simple and easy way to import maps and display information over an aerial image, and best of all, Google Earth is used ubiquitously. For these reasons, Golden Software has added the ability to export from Surfer 10 and up to KML and KMZ formats, so users can export their maps and open them directly in Google Earth.
This article will create a colored contour map, export it to a KML 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. The contour map is created.
- If available, the coordinate system information is automatically entered for the Contours layer. In this case, the map is in UTM coordinates.
- KML files require that the coordinates of the map be in Lat/Long units, and Surfer will automatically convert the coordinates of the map to lat/long upon export. However, this does require that a coordinate system for the map is specified. To check this, click Map in the Contents window, and in the Properties window click the Coordinate System tab.
- If there is a coordinate system specified, then you can skip to the next step. If not, click the Change button, select the coordinate system for the map and click OK.
- Add any color and customizations to the map. For example, select Contours in the Contents window.
- In the Properties window, on the General page, check the Fill contours check box.
- Click the Levels tab and change the Level method to Advanced.
- Click the Edit Levels button.
- In the Levels for Map dialog, click the Line column header.
- In the Line dialog, select Gradational in the Properties section.
- Click the Color button, and in the Colormap dialog select the Rainbow preset.
- Click OK and OK.
- In the Levels for Map dialog, click the Fill column header.
- In the Fill dialog, click the Foreground Color button.
- In the Colormap dialog, select the Rainbow preset and move the Opacity slider to 50%.
- Click OK and OK.
- In the Levels for Map dialog, click the Label column header.
- Change the Set value to 0 and click OK.
- Click OK in the Levels for Map dialog.
- 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, choose to save it in Google Earth KML format, and click Save.
- Click OK in the Export Options dialog and the KML file is created.
- Open Google Earth.
- In 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 transferred.
Open the KML file in Google Earth and the map is automatically placed in the correct location over the aerial image.