News Updates And Latest Blog Entries

Saturday, November 14, 2009

Virtual Reconnaissance

***WARNING*** this is a post for all you map geeks.

Google Earth

Google Earth is an excellent free tool for scouting a mountain biking venue before you go there. Google has wrapped aerial photography for the entire Earth over a digital topographic model so that one can view any area in three-dimensions. You can literally fly like a bird through the terrain. You can see your selected destination from a birds-eye view or tilt the surface as if looking at it from the side; you can also spin the view around so you can look at the 3-dimensional surface from any geographical direction. Google Earth is coupled with Google Maps powerful location search engine so you can just type in a name of a place, town, latitude/longitude etc. and zoom right to your locale of choice.

Click on image to enlarge

Step 1: download Google Earth if you don’t already have it on your computer.

Step 2: play with Google Earth to become familiar with it’s navigation tools.

Tip 1: set the vertical exaggeration to the maximum value to get a better feel for elevation. Go to Tools, then Options, go to the 3D view tab and set the elevation exaggeration to 3.

Tip 2: if you have a mouse with the roller wheel, then you can use these handy shortcuts:
1. Hold down shift key and roll wheel – this tilts the view
2. Hold down Ctrl and roll wheel – this spins the view

I remember the first time I played with Google Earth; frantically trying to think of all the amazing places I’d been and zooming down from the sky to see them on my computer screen – talk about nostalgia.

Example 1:
Type Brady’s Run in the Google Earth search window. Then use the navigation tools to zoom in and out and tilt and spin the view to see the killer climbs you could be riding if you go there.

What makes Google Earth really powerful is when it’s used in conjunction with some other free on-line services, namely GARMIN Connect and a free on-line topographic map streaming service.

GARMIN Connect
Step 3: Go to GARMIN Connect
Go to the Explore tab and click activities. This brings up an interactive map and search options display. Use the map interface to zoom to your venue of interest (try Brady’s Run as an example*). Click Show Filter on the search display panel and select mountain biking as the activity type and click Search. If you get way too many hits, then use another one of the search criteria to narrow the search, e.g. set Time Period to last 365 days.

*Tip 3: I have found the keyword search is not very affective as the search uses the search word literally (i.e. if you searched Brady’s Run it searches for the exact spelling with the apostrophe and all, also some GARMIN Connect users may not even use the venue name in their activity name – they may have called it Wednesday MTB ride or something even more esoteric).

Select a ride you like the look of. I selected because this guy rode on both sides of the valley. Now you see this particular persons ride stat’s, i.e. this ride was 6.46 miles and it took 1 hour and 50 minutes.

Tip 4: By using the Player option on the activities page of GARMIN Connect you can view the ride in a matter of seconds. This is particularly useful for seeing what direction the trails were ridden in. This can also be achieved in Google Earth using the little tool bar that appears when you bring in the ride.

Click on image to enlarge

Tip 5: Be wary of elevations shown in GARMIN Connect. Unless the GSP device used had a barometric altimeter the elevations can be wildly wrong. The type of device used is listed on the activity summary page. Devices to trust include the: Garmin Edge 305, Edge 705, and Edge 500.

On the selected activity page go to Export and select Google Earth and click Open. Now this route will appear in Google Earth. Explore.

Click on image to enlarge

MOTION BASED ( is another site with good regional mountain bike activity coverage.

Topographical Maps
Prefer to see routes on USGS topographical maps rather than an aerial photograph? If so, then download a free USGS Topographical map kmz file. Go to:
Download the USGS Topographical Overlays

Once you have saved this file to your computer, in Google Earth go to File then Open and browse to the file and click Open. Now you can view the route on a 3-dimensional topographic map.

Click on image to enlarge

Other Maps
Want to see another maps in Google Earth - may be a publicly available digital map with all the mountain biking trails on it? Find the map of choice. If it’s not in a jpg format, then convert it. is a free online document conversion utility that works well for this purpose.

Example 2:
Let’s use Blue Knob State Park as an example. Go to the DCNR’s webpage to download a PDF of the Blue Knob map.

Convert the file to a jpg format. And then go to Google Earth and zoom to Blue Knob State Park. Go to Add and then Image Overlay. Browse to the jpg of your map and using the green tools on the page stretch, rotate and move the map to fit. Once you’ve stretched the map to fit the real world, click Open.

Click on image to enlarge

Tip 6: The map stretching is best done with the 3-D terrain model turned off. Under Layers tab uncheck Terrain. Just don’t forget to turn it back on when you start exploring

Now add a GARMIN Connect activity for Blue Knob (I choose this one: And explore virtually.

Tip 7: If you want the routes, topographic maps, and/or the other maps you brought into Google Earth to be there next time you open Google Earth then right click on them under the Places tab and click Save to My Places

Tip 8: If all this wasn’t enough – you can also use Google Earth just like Google Maps to get directions from your home to the trail head.

I hope you have fun virtual exploring. Google Earth has been a fantastic tool for me when trying to get a feel for new places I want to ride. It also helps me have a get a mental picture of a place before I go there so I’m less likely to get lost.

It is Pennsylvania Dirt's goal to have all its Suggested Routes in a downloadable Google Earth format as well as all the trail maps stretched to fit the real world. Stay tuned…..

Simon T

1 comment:

  1. I fall, I rise, I make mistakes, I live, I learn, I've been hurt but I'm stronger, I'm human, I'm not perfect, but I'm thankful.

    Flights to Abuja | Cheap Air Tickets to Abuja


The Latest From Local Mtb Sites and Blogs