PTA Site Map / www.pinhotitrailalliance.org
The Pinhoti Trail
A Southeast Region Appalachian Trail Connector
The Ramen Chronicles ~ 2
1 / 23 / 06
The Wheel vs. GPS, A Civilized Conversation
From Bubba:
Billy Bob, haven't talked to you in a while. I've been experimenting with a new
GPS unit I got for Christmas. It's a pretty awesome thing. Purchased some software to
download the tracks into also.
While figuring the thing out, I've been doing some section hiking on Section 9. I hiked
from Bull Gap all the way to Sherman Cliffs the other day, and found some oddities --
most notably the mileages. According to the GPS, the length of that section is 7.31 miles.
I noticed on the hmtc website that you have it listed as 7.6 miles.
I don't know what to believe. What do you think could account for the differences? I
stayed on the trail, and can't imagine that I didn't walk dead center in the middle of the
trail (sometimes in the left track, sometimes in the right, etc.) the whole time would add
up to 1/3 of a mile.
I'm attaching a jpg of the southern section (Bull Gap to first power line easement) so you
can see how detailed the software gets. By the way, there's a 546 foot elevation change
in that first 2 miles.
From Billy Bob:
Hey Bubba! I've never been able to really figure out why GPS and wheels never seem to
agree. If you add up the mileages from the USFS ~ Pinhoti topo maps they sell, you'll get
103.8 miles from Porter's Gap to the 278 trailhead. I came up with 108.8 miles on the
wheel. That's a whopping 5.0 mile difference! (this was my reason for measuring the
entire trail a second time a year later, which also showed the same 5.0 mile difference}
Who's right? I always have the same thoughts each time that the differences in the two
methods are presented to me.
The first is that there are probably plus and minus factors to everything mankind creates
/ does. Is what you see on paper a true reflection of reality, or are there always slight
convenience compromises made to accomplish the desired result?
Here's something I did regularly that would shock the true anal-ite. Whenever my wheel
would come up against a blowdown, I would mark the spot where it stopped with my foot.
Then I would lift the wheel over and set it down on the other side. Then I would lean over
the tree and observe the two spots for a moment and say, yep, that's about a foot and a
half Bubba. : ) Nothing major but it is still a convenience compromise. If I were a brain
surgeon, you would surely die.
The second thought I have is about how each reads terrain. Here's an example. Say you
have a stretch of trail that's 50' long that you can verify with a tape measure. Now say
that there is a 10' deep gulley in the middle of that stretch. If you ran a wheel down into
the gulley and back up the other side it would read more than 50'. The question I've
always had is weather the GPS goes down into the gulley with you or does it read it as the
crow flies?
There are probably answers, as opposed to opinions, to these questions out there
somewhere but I don't have access to them. In the end, I finally agree to let them
disagree and view them as just two opposing, complimenting views.
Of course a lot of folks hiking from, say Bull Gap to the fire tower, would be just as happy
with; ‘It's about 10 miles and the average person travels about 2 mph, so after you add in
a couple of breaks it will take you about 5 and a half hours.’ : )
Which reminds me of a third way to present trail information. Have you read
MountainDog's journals on Lees board? He uses the hour method and I thought it was very
credible and I've encouraged him all along.
I think GPS is very credible too and I assume there is probably a large group of GPS folks
out there who would love to be able to access the info you're collecting. If you've ever
thought about building a website or writing a book, I'd say go for it!
This probably doesn't say much for my life experience, but running that wheel up and down
the trail for 50 weekends was the most exciting thing I've ever done. Between that and
the HMTC website, I've been challenged on a lot of different levels.
I've tried to encourage people the last few years to build more Pinhoti related websites:
Flwrhead / wildflowers, Dynamo / fishing holes, Philip Alexander / critter poop,
MountainDog / a trail guide. Anyway, the map is great. I love maps. Keep it up!
From Bubba:
Billy Bob, here's a view of the GPS map from the Sherman Cliffs area southward towards
the big set of switchbacks.
From Billy Bob:
Hey Bubba! Another fine map. Thanks. You do know what's going to happen when people find
out you can do this right?? This is great stuff Bubba.
From Bubba:
Billy Bob, ever wondered exactly what the Cheaha - Pinhoti Loop looked like from space?
7.29 miles, 1,576 feet of total climbing, 1,576 feet of total descending. Starting at the
Cheaha trailhead and making the loop, the low & high points are 1,871and 2,348 feet. I'm
attaching the 2-D and 3-D versions of this map here.
Your idea made me think. I'd never really thought about whether the GPS could "see"
gullies of actual walking, or if it skimmed over them looking for total distance. The GPS I
just got has 2 distances listed within the data -- one for total distance, and one for total
ground distance. For this map of the Cave Creek - Pinhoti loop, the total distance is listed
as 7.25 miles, but the actual ground distance traveled is 7.29 miles. .04 miles difference
- about what you'd expect allowing for terrain that the satellites can't see.
I'm gonna go back and look at the Bull Gap to Sherman Cliffs file again to see what the
differences are, then maybe re-walk the section again. Maybe that will explain the 1/3
mile in question somehow.
From Billy Bob:
Hey Bubba! Man, that must be some kind of wicked software you have! In order to read
ground distance, wouldn't it have to do something like measure from waypoint to waypoint
and then calculate that figure against the elevations it reads on the topo map??? Gee,
that's too mind boggling to even think about!
I looked up the elevation that I have for Hernandez Peak that I got from the FS topo
map and it is 2344' so your altimeter is dead on for the high point. The low point must be
over on Cave Creek somewhere.
These maps you're cooking up are a prime example of why folks love maps. I love to see a
bigger picture of what's around me, That's why I like to hike in the winter when the
leaves are down.
Sounds like you're having a great time figuring this thing out.
Thanks for sending all of this along.
Here are some of the extended readings I have from Bull Gap:
0.0000 Bull Gap
2.1919 1st Power Line
6.5464 Big Power Line
7.5009 Heath Cliffs
7.6049 Sherman Cliffs
17.9852 Porter's Gap
From Bubba:
Billy Bob, you must be a technologically minded person! The software does indeed take
into account the change in elevation from waypoint to waypoint, then computes that via
some algorithm into the "distance traveled" versus the "total distance." As with anything,
it's probably not right on -- but an approximation.
The software is called Terrain Navigator by MapTech:
http://www.maptech.com/land/terrainnavigator/index.cfm
Here's my GPS unit:
http://www.garmin.com/products/gpsmap60c/index.jsp
Thanks for the Bull Gap extended readings!
From Billy Bob:
Hey Bubba! Pretty amazing stuff. Thanks for the links. This should give GPS'ers a lot of
credibility in the eyes of the "old schoolers".
Of course with wheels, you're dealing with cheap little mass produced plastic odometers,
so I'm sure we're doing a little approximation ourselves. : )
11 / 26 / 05 ~ Wanderlust ~ Nimblewill Nomad
Unquestionably, we each possess that instinctive, deep-down drive called “wanderlust.”
Few of us, however, have given in to it, to just go. Ahh, but those of us who have, those of
us who seized the moment, who pursued that “fire in our gut,” we’re the truly blessed; we’
re the ones bestowed the opportunity to chase our dreams”…into the hazy blue…”
When I’m out and moving, there’s such an incredible feeling of vitality, of strength, of
freedom, freedom beyond description, beyond comprehension, most-near nirvana. Consider
then, in addition, finding the Lord right there beside, through every hardship, through all
the tough times, especially through the frequent crushing episodes of consuming doubt and
despair--consider finding the Lord, always there. What joy, to be lifted and carried along
without the least earthly burden. It’s intense, intense. So, I must tell you--such a journey
is really not a journey at all, not in the least; it is, indeed, a pilgrimage.
Ahh, but you see, life on the move is the ultimate life of freedom; it’s the totally
unfettered way--bound only by what’s on one’s back, to fade “…into the hazy blue…” like
“…those of us lost to the dust outward blown…,” “who have gone and never come back…;”
we come the closest to truly taking wing, to flying. Indeed, our lives soar the nearest to
heavenly bliss--on this Earth.
PTA Site Map / Top of Page ^-^
The Pinhoti Trail
A Southeast Region Appalachian Trail Connector
The Ramen Chronicles ~ 2
1 / 23 / 06
The Wheel vs. GPS, A Civilized Conversation
From Bubba:
Billy Bob, haven't talked to you in a while. I've been experimenting with a new
GPS unit I got for Christmas. It's a pretty awesome thing. Purchased some software to
download the tracks into also.
While figuring the thing out, I've been doing some section hiking on Section 9. I hiked
from Bull Gap all the way to Sherman Cliffs the other day, and found some oddities --
most notably the mileages. According to the GPS, the length of that section is 7.31 miles.
I noticed on the hmtc website that you have it listed as 7.6 miles.
I don't know what to believe. What do you think could account for the differences? I
stayed on the trail, and can't imagine that I didn't walk dead center in the middle of the
trail (sometimes in the left track, sometimes in the right, etc.) the whole time would add
up to 1/3 of a mile.
I'm attaching a jpg of the southern section (Bull Gap to first power line easement) so you
can see how detailed the software gets. By the way, there's a 546 foot elevation change
in that first 2 miles.
From Billy Bob:
Hey Bubba! I've never been able to really figure out why GPS and wheels never seem to
agree. If you add up the mileages from the USFS ~ Pinhoti topo maps they sell, you'll get
103.8 miles from Porter's Gap to the 278 trailhead. I came up with 108.8 miles on the
wheel. That's a whopping 5.0 mile difference! (this was my reason for measuring the
entire trail a second time a year later, which also showed the same 5.0 mile difference}
Who's right? I always have the same thoughts each time that the differences in the two
methods are presented to me.
The first is that there are probably plus and minus factors to everything mankind creates
/ does. Is what you see on paper a true reflection of reality, or are there always slight
convenience compromises made to accomplish the desired result?
Here's something I did regularly that would shock the true anal-ite. Whenever my wheel
would come up against a blowdown, I would mark the spot where it stopped with my foot.
Then I would lift the wheel over and set it down on the other side. Then I would lean over
the tree and observe the two spots for a moment and say, yep, that's about a foot and a
half Bubba. : ) Nothing major but it is still a convenience compromise. If I were a brain
surgeon, you would surely die.
The second thought I have is about how each reads terrain. Here's an example. Say you
have a stretch of trail that's 50' long that you can verify with a tape measure. Now say
that there is a 10' deep gulley in the middle of that stretch. If you ran a wheel down into
the gulley and back up the other side it would read more than 50'. The question I've
always had is weather the GPS goes down into the gulley with you or does it read it as the
crow flies?
There are probably answers, as opposed to opinions, to these questions out there
somewhere but I don't have access to them. In the end, I finally agree to let them
disagree and view them as just two opposing, complimenting views.
Of course a lot of folks hiking from, say Bull Gap to the fire tower, would be just as happy
with; ‘It's about 10 miles and the average person travels about 2 mph, so after you add in
a couple of breaks it will take you about 5 and a half hours.’ : )
Which reminds me of a third way to present trail information. Have you read
MountainDog's journals on Lees board? He uses the hour method and I thought it was very
credible and I've encouraged him all along.
I think GPS is very credible too and I assume there is probably a large group of GPS folks
out there who would love to be able to access the info you're collecting. If you've ever
thought about building a website or writing a book, I'd say go for it!
This probably doesn't say much for my life experience, but running that wheel up and down
the trail for 50 weekends was the most exciting thing I've ever done. Between that and
the HMTC website, I've been challenged on a lot of different levels.
I've tried to encourage people the last few years to build more Pinhoti related websites:
Flwrhead / wildflowers, Dynamo / fishing holes, Philip Alexander / critter poop,
MountainDog / a trail guide. Anyway, the map is great. I love maps. Keep it up!
From Bubba:
Billy Bob, here's a view of the GPS map from the Sherman Cliffs area southward towards
the big set of switchbacks.
From Billy Bob:
Hey Bubba! Another fine map. Thanks. You do know what's going to happen when people find
out you can do this right?? This is great stuff Bubba.
From Bubba:
Billy Bob, ever wondered exactly what the Cheaha - Pinhoti Loop looked like from space?
7.29 miles, 1,576 feet of total climbing, 1,576 feet of total descending. Starting at the
Cheaha trailhead and making the loop, the low & high points are 1,871and 2,348 feet. I'm
attaching the 2-D and 3-D versions of this map here.
Your idea made me think. I'd never really thought about whether the GPS could "see"
gullies of actual walking, or if it skimmed over them looking for total distance. The GPS I
just got has 2 distances listed within the data -- one for total distance, and one for total
ground distance. For this map of the Cave Creek - Pinhoti loop, the total distance is listed
as 7.25 miles, but the actual ground distance traveled is 7.29 miles. .04 miles difference
- about what you'd expect allowing for terrain that the satellites can't see.
I'm gonna go back and look at the Bull Gap to Sherman Cliffs file again to see what the
differences are, then maybe re-walk the section again. Maybe that will explain the 1/3
mile in question somehow.
From Billy Bob:
Hey Bubba! Man, that must be some kind of wicked software you have! In order to read
ground distance, wouldn't it have to do something like measure from waypoint to waypoint
and then calculate that figure against the elevations it reads on the topo map??? Gee,
that's too mind boggling to even think about!
I looked up the elevation that I have for Hernandez Peak that I got from the FS topo
map and it is 2344' so your altimeter is dead on for the high point. The low point must be
over on Cave Creek somewhere.
These maps you're cooking up are a prime example of why folks love maps. I love to see a
bigger picture of what's around me, That's why I like to hike in the winter when the
leaves are down.
Sounds like you're having a great time figuring this thing out.
Thanks for sending all of this along.
Here are some of the extended readings I have from Bull Gap:
0.0000 Bull Gap
2.1919 1st Power Line
6.5464 Big Power Line
7.5009 Heath Cliffs
7.6049 Sherman Cliffs
17.9852 Porter's Gap
From Bubba:
Billy Bob, you must be a technologically minded person! The software does indeed take
into account the change in elevation from waypoint to waypoint, then computes that via
some algorithm into the "distance traveled" versus the "total distance." As with anything,
it's probably not right on -- but an approximation.
The software is called Terrain Navigator by MapTech:
http://www.maptech.com/land/terrainnavigator/index.cfm
Here's my GPS unit:
http://www.garmin.com/products/gpsmap60c/index.jsp
Thanks for the Bull Gap extended readings!
From Billy Bob:
Hey Bubba! Pretty amazing stuff. Thanks for the links. This should give GPS'ers a lot of
credibility in the eyes of the "old schoolers".
Of course with wheels, you're dealing with cheap little mass produced plastic odometers,
so I'm sure we're doing a little approximation ourselves. : )
11 / 26 / 05 ~ Wanderlust ~ Nimblewill Nomad
Unquestionably, we each possess that instinctive, deep-down drive called “wanderlust.”
Few of us, however, have given in to it, to just go. Ahh, but those of us who have, those of
us who seized the moment, who pursued that “fire in our gut,” we’re the truly blessed; we’
re the ones bestowed the opportunity to chase our dreams”…into the hazy blue…”
When I’m out and moving, there’s such an incredible feeling of vitality, of strength, of
freedom, freedom beyond description, beyond comprehension, most-near nirvana. Consider
then, in addition, finding the Lord right there beside, through every hardship, through all
the tough times, especially through the frequent crushing episodes of consuming doubt and
despair--consider finding the Lord, always there. What joy, to be lifted and carried along
without the least earthly burden. It’s intense, intense. So, I must tell you--such a journey
is really not a journey at all, not in the least; it is, indeed, a pilgrimage.
Ahh, but you see, life on the move is the ultimate life of freedom; it’s the totally
unfettered way--bound only by what’s on one’s back, to fade “…into the hazy blue…” like
“…those of us lost to the dust outward blown…,” “who have gone and never come back…;”
we come the closest to truly taking wing, to flying. Indeed, our lives soar the nearest to
heavenly bliss--on this Earth.
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