Mapping the Sheltowee

Ma Rose · on trail Joined: 27 Feb 2008 Posts: 37 Location: Berea

This is a series of just-out-of-curiosity questions, because I know virtually nothing about GPS except that it uses satellite triangulation and there is some error built in. So, please forgive my ignorance, and bear with me if I ask something stupid...

If I remember correctly, you hiked the entire ST to collect GPS data. Yes?

How frequently do you have to take a reading to get a really accurate map of a trail?

How much error is involved?

If you had to guess, how accurate would you say the mile markers on the ST maps are (off by 1%, 10 ft, etc.)?

How did you figure out distances from the data collected?

How do you measure distances on different kinds of trail (for example: a long, straight stretch along a riverbank vs a series of steep, tight switchbacks)?

Are there places where you can't get a GPS signal? If so, what do you do?

Do you think that measuring mileage with a GPS is more accurate than old-fashioned methods, like a measuring wheel?

I'm not questioning the accuracy of your maps. I have the southern ST series and the RRG map and really like them. I'm just extremely curious about how the whole process works.

Carey

jbd · Posted: Thu Mar 10, 2011 10:12 am Post subject:

I met one of the guys who was at the time doing the GPS tracking of the trail. At the time I knew nothing of the Sheltowee Trace and thought it seemed to be an "odd" hobby to be out tromping around the woods taking GPS readings and altimeter readings. He doesn't post much here but I really hope he will respond to your questions because I think it would be intersting to hear his story and how he did the work that we are all benefitting from now.