Even though I find the R solution easier, I'm sure not everyone agrees with me, so here's the Google Earth way to import a bunch of GPS tracks and map them:
Export to TCX
From inside Garmin Training Center or other GPS device software, export a huge TCX file with all your tracks.
Mapping in Google Earth
Select File -> Open. Change the dropbox for "Files of type" to "Gps", and then find your file and open it. Make sure the "Create KML LineStrings" box is checked and the "Create KML Tracks" box is unchecked. This will save us some work later.
Next, zoom in, zoom out, and recenter as desired. If you want North to be up, you can click the "N" in the compass in the upper right.
In the layers (bottom left), I personally like to check Roads and uncheck everything else.
In the places (just above layers), right click "GPS device" and select "Properties". Click over to the "Style, Color" tab, and then click "Share Style".
I like to use the following settings:
- Color: red
- Width: 3.0
- Opacity: 100%
- Opacity: 0%
- Opacity: 0%
Make sure you've selected all the dates you want on the date slider. Then you can select "Print" to export to a PDF, or you can take a screenshot.
And that's all there is to it. Large maps may take a long time to load and edit.
This post is one part of my series on Mapping GPS Tracks.