johnnyb wrote:Probably don't need to beat this topic to death any more, but I've heard (meaning don't have any valid data) that gps units might not do so well with switchbacks.
Anybody else hear this? Anybody got any data true/false?
Just wondering,
John.
There has been some claims about how accurate the gps units are so
I fished around a bit and found some surprising information about how accurate the latest gps receivers actually are. Including wrist bound models.
I called Garim and asked about how accurate their best units are for measuring trails. They told me that these units aren't really designed for accuracy in mountain trails. More for approximate readings where there is no obstructions blocking required satellites. They told me that the units take readings anywhere within an 18 foot wide circle around where ever the unit is. And as you know our trails veer and twist randomly from side to side and could not possibly be measured accurately with an 18 foot wide instrument.
And this would be under best conditions.
Also noted was that these units are even less accurate with the elevation and loss gain which needs to be considered to be accurate in this. The 3rd dimension, if you will. Trails go up and down as well as side to side, randomly, for those reading this who have never been on a mountain trail before.
Here the 18 foot swath is enlarged to a
whopping 100 feet. (imagine being surrounded by an 18 foot x 100 foot bubble and trying to measure a trail with it!)
There have been some amateur experiments that confirm this. When using a gps and comparing the return result, in ideal conditions, without a witness, was declared "accurate" when showing an inconsistency of over 33 yards!
How a gps would work on this particular trail is a guess at best. I wouldn't use a gps to get a reliable distance.
I got nothing against gps units. They have other features that can help approximate elevation, way points and other things that can help in hiking safety. But when it comes to measuring distances on our trails, the numbers that they display have no meaning whatsoever. I mean I could do better using a 100 foot tape!
If this hurts any ones feelings let me say take your feelings and set them aside. I'm talkin' facts here.
I do believe that some day they will become dead on where there is no bubble around it. Those days will eventually be here. But not now.
If you really wanna know how long a trail is, I mean
really wanna know then use a wheel. (unless there are ducks on the trail, but we have a guy that takes care of those so no worries.)
To me using a gps to measure a trail is like trying to duplicate the mona lisa using a paint roller.
And, AND they don't get shiny when you walk off the trail either. I asked about that too!
('cuz it did beat me up a bit).
