QGIS is an excellent piece of free GIS software. This tutorial explains how to use Site Scan and QGIS together to generate topo/contour plots for earthwork, client updates, planning civil work, and accurately estimating jobs.
5. Now, create contours by navigating to the Contour tool via Raster>Extraction>Contour.
In the Contour dialog box, select the newly created clipped raster as the input and select an output filename and file type.
You can produce contour/topos in the following formats:
In a couple seconds, the contour shapefile will be created.
6. Right click the newly created file which now appears in the Layers window and select “Save As”
Once saved, you can use this file in whatever planning or earth work program you need.
7. To create a KML file for viewing in Google Earth, select “Keyhole Markup Language” as the output format, and select a filename for the output file.
8. Open resulting KML file in Google Earth!