This is the 3rd (and last) in a series on GPS tracking of skiers, and more to the point, the overlaying of ski maps into Google Earth in order to put that data into reference. So after asking someone way better at Photoshop than me to “stretch” that ski trail map of Heavenly Lake Tahoe and make it fit Google Earth, it has become VERY clear that those maps aren’t even close to accurate.
Photoshopping the map & stretching/skewing it to fit, then overlaying the sides to be accurate, it’s still obvious that there is no real scale built into these maps. The Gondola is nowhere near reality:
So we aborted the mission of overlaying this map in favor of simply recreating the runs as Google Earth “paths.”
Here is what it looks like once you add a number of “paths” and “placemarks” in Google Earth, using the map as a reference, and the satellite photo with the missing trees as evidence of where the ski runs actually are:
The paths are color-coded based on type (typical green/blue/black difficulty based on the map) and the Gondola is in red.
If you were using GPS Insight to say, track your Snowcats (which are used to groom the runs regularly), you would be able to run reports on which runs were groomed on which days, for how many hours, etc. This is actually something we’re starting to see some interest in from some ski resorts which is part of the motivation for this exercise (if I had thought about it in advance I could have written off the trip!).
You can see how accurate this is if you take a little time to properly map the trails — We show activity skiing right along Orion, Skyline Trail, and Ridge Run (as well as us taking the lift up ABOVE Ellies — I didn’t take my 8 year old snowboarder on this black (he probably would have done better than me, actually).
Using a combination of a ski trail map and Google Earth with recent imagery, it is easy to see which runs particular GPS data recorded activtity on.
We’re going skiing tomorrow in Pinetop AZ at “Sunrise” park (www.sunriseskipark.com) — here’s their much more straightforward trail map.![]()
I’m done overlaying them, I think everyone gets the point now (on to more vehicle based GPS tracking topics next!)
Thanks,
Rob.

January 17th, 2009 5:55 pm
I was thinking about tracking those Snowcats the whole time, Rob. And you thoughts about making the trip deductible (or at least aprtly deductivble) ought to resonate with some as well.
When I was selling in the GPS tracking field the first thing I did was put a demo unit on my personal car and there it stayed … after all what better way to show a potential client what the unit looked like, how easy it was to see my driving performance, etc.
But that unit made me more money in a way that had nothing to do with sales. At tax time I found (could I be the only guy who made this screw-up?) that the business mileage so laboriously noted in the ubiquitous little Dome Auto Miles log was about 4000 miles short of the miles on my odometer for the year.
Obviously some of those miles were personal, so I couldn’t just add them on my deductible business mileage. But just as obviously some of those ‘lost’ miles had to be business related.
Well, d’oh, that’s why I have a tracker, isn’t it? I ran reports month by month for the preceding year and found well over 1,000 miles that were totally supportable to IRS standards … at 2008 rates that’s worth more than $500, way more thna the cost of the unit itself.
So if you’re in the GPS business? The first person to track, 24-7, is _you_