On Mon, Feb 15, 2010 at 4:32 PM, Jim Thill - Hiawatha Cyclery <thill....@gmail.com> wrote: > I always figured it was the other way around. Web-based mapping will > not count climbing (or the non-horizontal component of distance > traveled) because of the coarseness of digital elevation maps. For > example, if the topo model has 10-foot contour intervals, how does the > mapping software deal with all the up and down you might do without > ever crossing a contour line? > > GPS should record elevation changes more accurately, and both GPS and > cycle computers should record distance traveled more accurately than > mapping software does. In the old days (10-15 years ago), GPS > elevation measurements were suspect because there weren't always > enough satellites to triangulate accurately in the 3rd dimension. I > think this has improved lately. > > Anyway, I've always found the cycle computer to be ~2% higher in > distance than a gmap plot of the ride would indicate. I attributed > this to the lack of topo correction in gmaps. >
It's the same reason why the coastline of any island appears to be infinitely long - it depends entirely on how long your smallest measuring stick is. if you measure base on one wheel rotation then clearly you miss the extra distance going up and down the lip of a small pothole, though you did traverse the distance. -sv -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bu...@googlegroups.com. To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
