At this point, you have a gpx file with coordinates – including the hoorizonal and vertical values.
The next step is to generate contours from the points. To do this, we will use QGIS, a free GIS software that you can download from their website. Once you have QGIS open, follow these steps:
- Add the gpx file to your project. In the top navigation bar, click on Layer > Add Layer > Add Vector Layer, select your file and then click Add
- Select the layer called “track_points” or whatever layer has the greatest number of features in it (hint, these are your points). At this point, you should see all of the points created using Google Earth and GPS Visualizer on your screen.
- Next, turn the points into contours. In the top navigation bar, click on Vector > Contour. Make the following parameter adjustments:
- Data value drop down needs to be set to elevation or “ele”
- Method drop down: Fixed contour interval
- Interval: Your choice, I selected 0.5 m
- Number: You will likely have to tweak this until you get the desired result.
- Click Add. At this point, you should have your contours created which can be download in any format!