Re: GPS to calculate mileage

[Lynne Glazer <lglazer@cyberg8t.com>]

We used Topo! and the gps to do the Norco ride, but it didn't account for
how much the Santa Ana river moved due to El Nino (heck it moves *every*
year, though up to 100 feet in some places last year) and how all the
trails had to be recut.

We did enjoy the elevation profiles, and used the corrected Topo! printouts
for our rider maps.  We must've had 400 waypoints in the original plotting
and compared it to mileage from the only vehicle that had access to the
course, the park ranger's (mechanical) mule.

Lynne
Norco Riverdance Ride

>Much easier and better than method 2 is to use a computer and the
>software/topo maps from Topo! (http://www.topo.com).  On the trails we used
>for our recent Sage Hill NATRC ride, where we could get to most of them to
>check with vehicle odometers, the comparison between the odometer and the
>topo software was well under 10% (in fact, given that the odometer only
>reads in 0.1 miles, the comparison appeared to be dead-on).  The GPS can be
>very handy for recording waypoints and then letting you find them on the
>topomap on the computer for places where your trail is doing a lot of cross
>country.  The topo software prints out trail elevation profiles as well --
>plus it generates your ride maps.  Most of California -- in fact large
>portions of the US recreational areas -- are now available on the CDs.
>
>
>-- Lynn K. (Santa Ynez, CA)
>   http://www.silcom.com/~lkinsky
>