Visualizing GPS Tracks with Google Earth

It's fun to share your activities that you record with your GPS. There are a few easy ways to share the data and maps, including the Garmin Connect and RunSaturday web sites, and by saving images from SportTracks and posting them to DailyMile or emailing to your friends. You can make your story even more interesting by using Google Earth to create 3d images that show the terrain and even animated fly-overs of your activities.

The image above is a great example of a 3d image. It shows the GPS track recorded while skiing at Kirkwood superimposed on an image of the ski hill. Notice that the perspective is looking up toward the mountain, not straight down onto a flat map. This makes the image much more dramatic than the flat maps we typically share. Can you imagine skiing down those steep faces?

Making these type of images is simple. You start by recording your activity with your GPS just like you normally would. Turn on your GPS, make sure the satellites lock in, hit the start button, go have fun outdoors, then hit stop when you're finished.

I use SportTracks to track my runs. It's great as a logbook. It also provides some nice features including data smoothing and elevation correction via a plug-in. It's also very easy to export from SportTracks to Google Earth. Here's where the fun begins.

When you export to Google Earth be sure to set split markers. I usually use 1 mile increments. The split markers are important for creating animated fly-overs.

Once you have the activity open in Google Earth you'll want to enable the terrain layer. The layers panel is on the lower left of the Google Earth window. Expand the panel if it's not visible, then scroll down to the Terrain section of the list and click the check-box to enable the terrain.

It's also useful to enable terrain exaggeration. You can find this on the Google Earth Preferences panel. Somewhere between 1.5 and 2.5 works best.

Now you can set your perspective by using the navigation controls in Google Earth. You can move left and right, forward and backward using the arrow keys. The tilt angle is controlled by holding down the shift key and then hitting up and down arrow. You can rotate your view by holding down shift and hitting the left and right arrow keys. Zoom in and out using your mouse scroll wheel or the on-screen zoom controls. Once you get the view you want you can save an image using the File, Save, Save Image menu options.

To create a spectacular animated fly-over you can set the perspective for each of the mile markers SportTracks created when you exported the activity. Highlight the first mile marker on the activity panel, set your view using the navigation controls, then snapshotting the view of the split marker. Do this for each split mark, then play the activity using the play arrow on the left hand side. You can then save the activity as a KMZ file and post it online or email it for your friends to play in google earth.

I created a fly-over of the Ohlone Wilderness 50K Trail Run ultra marathon course. You can download a copy at http://tinyurl.com/ohlone50k Download the .KMZ file, open it in Google Earth, then hit the play button. I think you'll agree that the animated fly-over with perspective and terrain tells a better story than a two dimensional map.