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. On Feb 15, 3:10 pm, Eric Norris <campyonly...@me.com> wrote: > Can't compare web to GPS, but I've found over the years that both > calculate more climbing than is shown by an altimeter watch or bike > computer. The altimeter typically shows about 30% less altitude gain, > probably because the mapped versions add up every little up while most > altimeters ignore small gains. > > -- Eric Norriswww.campyonly.comwww.wheelsnorth.com > > On Feb 15, 2010, at 12:59 PM, doug peterson <dougpn...@cox.net> wrote: > > > In mapping out routes, I've noticed big differences in both distance > > and elevation gain between GPS and plotting the same route on web > > based mapping services. Distances can be off by 5%-10% and elevation > > by double. The web based systems are always higher than GPS. Has > > anyone else encountered this? It's entirely possible I'm doing > > something wrong on the web based systems. > > > dougP > > > -- > > 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 > > athttp://groups.google.com/group/rbw-owners-bunch?hl=en > > . -- 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.
