GPS data collection parameters?

[Jim Tomlin]

I will be visiting the North District of SNP this weekend and can
collect data for the trails that I hike. I'll sign up for the trail
segments on the official Lucidity sign-up sheet.

What data collection parameters should I set my DeLorme PN-40 for? A
breadcrumb every N seconds, or every J feet? I got very nice tracks
for my recent AT backpack in SW VA using every 10 seconds (and walking
slowly), but I defer to the project managers how I should collect data
for this project.

It would be great to put the data collection parameters on the
Lucidity website so that everyone can refer to them. I looked for
them but couldn't find them.

Would there be any benefit to the project for me to use more than one
PN-40 at a time? I could easily run two or more of them...

Thanks,
Jim Tomlin

[Chris Mangold]

Jim:

    Yes, the collection protocols need to be up on the site and I am planning of taking advantage of the long weekend to get them on the site. 

     In short the committee came to the conclusion that 3 second bread crumbs walking at a normal speed gave us the accuracy we desired.  The data at Bears Den and data collected since then and forwarded to me has come out very nicely.  I don't see a need for collecting with more then one device unless you wanted to do comparisons of data collected with different settings.

      I will post the data collection protocols to the Web Site this weekend.

Thanks,

Chris

--
Chris Mangold
301-471-5758 (c)
301-898-7979 (h)

[Jim Tomlin]

Thank you! I'll set mine to 3 seconds and collect at that rate. My
"normal" pace is probably slower than the average "normal".

Jim T.

[Mrzac...@aol.com]

Would it make sense to do a deliberate 9 second pause and the end of each switchback to insure pegging the point of turn? Waypointing would take longer. Some steep runs would make for slow going. But we would have the point more reliably.

Steve

[Chris Mangold]

Steve:

   On trails where I have come across a hair-pin turn/switch back I have typically stopped for at least 3 seconds to make sure I collected a point at the apex of the switch back.  Are you suggesting 9 seconds to build in a averaging process for the switchback point?  

    I certainly don't have a problem doing this, I am working tonight on adding a page to the site to document all of are collection protocol decisions.  I certainly can add this is a best practice.

Chris 

[Mrzac...@aol.com]

Chris, I hate to sound trite, but the short answer is YES and I do not know! Yes, I suggest a 9 second count at the point of all switchbacks when using a 3 second collection criterion. BUT -

 

It seems plausible, makes our data collectors cognizant of the apparent greatest error source in the methodology (seems right but is this fact?), provides for averaging and provides cover for weak (non3D unless already excluded) signal, dropped datapoint, provides for improving data received from fast hikers and probably some other things escaping me at the moment. But then, it will require active effort on the part of the hiker, slow them down some (I would welcome the excuse for a breather on the uphill) and if it returns three points all would have to be averaged independently of the rest of the track.

 

Just a thought, it has worked for me in other situations, but we need to evaluate its usefulness for the project at hand. And consider the human compliance factor. Lastly, it kinda messes with the "just give me data" approach that I also agree with, but the track will permanently show those 3 or more points and so identify the "pausers" from the non pausers.

 

Maybe 9 seconds is too little for a good average value for the importance of the point? I do not know. Whomever processes the tracks will have to weigh in after trying some of them I suppose.

Thanks for asking,

Steve