[pct-l] Data Book Discrepancies

[Robert Henry]

Here's my view, as a navigator from Seattle..

Hikers can choose any coordinate system they want.  It only matters when
they have to coordinate with others, such as fellow hikers, outsiders you
meet up with at rendezvous points, guide books' descriptions of some
feature or opportunity, or emergency services. Hikers may find they have to
use old-fashioned things like "10 minutes hike north of X", "at the 10,360
elevation on creek Y", or UTM derived directly from the GPS or
interpolation from the edge labels on a topo map, or even position within
township, range and section.

It is unlikely that a message to emergency services "We need help at mile
post 777.7 on Halfmile's 2014 mapset" is going to be understood by those
agency's with any accuracy any time soon, but the other coordinates they
may easily understand.

At the end of the day (literally!) you will still stop where there's water,
or a view, or out of the wind, or food, or other hikers, or it is dark, or
you're just too tired to go on.  The fact that today's walk was 196.8
furlongs or 40.225 km or 25.13 miles that day simply isn't relevant; you'll
be more interested in what's for dinner anyway.


On Wed, Jun 11, 2014 at 9:35 AM, Barry Teschlog <tokencivilian at yahoo.com>
wrote:

> Jalan Wrote:
>
> I have seen other discrepancies as well  (data book, WP guide, half mile.
> Blacks guides, etcc )it would be nice to have an agreed upon standard but
> judging by recent posts , there is some rancor around this subject I've
> always been annoyed that the WP guides always refer to distance between
> points rather than overall mileage points but I guess that makes the data
> less susceptible to overall changes on the trail length re routes etc It
> seems like the PCTA should set the gold standard. If they have apparently
> the word has not gotten out
>
> Reply:
>
> In regards to ANY person's distances, no matter the source, I'd suggest
> its not so simple.  Even if everyone was on the same page as to exactly
> what the route is, everyone, when they walk it, is going to come up with
> slightly different distances depending on the equipment and methods
> used (and even the conditions under which the measurements are made -
>
> http://en.wikipedia.org/wiki/Error_analysis_for_the_Global_Positioning_System).
> Add to that, there are some parts of the "trail", or the route, that
> really beg the question as to how to measure them.
>
> A concrete example of this latter point that I'm very familiar with is
> between the southbound trail head and the northbound trail head at
> Snoqualmie Pass.  A quick Google Map of the route one would likely walk
> from trail tread at the southbound TH to (main thread) trail tread
> coming from the NB trail head indicates the distance is about 0.59 miles
> (and even that number has false precision associated with it).  OK, so
> is this included?  Where's the break point between Section I and Section
> J?  Which user (day / section or thru) is being measured for, since a
> section or day hiker isn't going to start under the I-90 bridge and go
> up the side trail northbound, or walk to the SOBO TH, but will drive to
> and leave from either trail head parking lot.  Note that I used the side
> trail access to the NB trail on the above estimate - even that is open for
> "debate" - is the right way to walk around on the road via the parking
> lot?  This is but one example, one I happen to know of
> specifically.  Multiply that by how many times up and down the trail,
> combined with the perpetual changes to the trail from year to year and
> it can be seen that of course distances are going to vary from source to
> source.  Which is right?  Shrugs, since it really doesn't matter, IMO.
>
>
> In the grand scheme of things, the above 0.59 miles, give or take, is "in
> the noise" as an engineer would say.  Arguing about tenths of miles, or
> even single digit miles, over the length of a 2,660 mile trail (give or
> take) kind of misses the inherent accuracy and precision of the
> measurement.
>
>
> After all, I say that 2,663 Angels can fit on the head of a pin and that
> other person who says that 2,662 or 2,665 can fit is so blatantly wrong
> that their
> motives must be pure evil and they're the spawn of Satan for even
> suggesting it.  Tongue firmly in cheek on that last part.
>
>
> YMMV (literally), HYOH, 2 cents, first to Canada loses, yadda, yadda, yadda
>
> Barry
>
> PS
>  - The snow is melting here in the great Pacific Northwest.  If you're
> interested in taking care of the PCT here, we have a work party at
> Stevens Pass June 28-29 and will start logging out south of Snoqualmie
> Pass probably the 4th of July weekend.  Our 3 day work party Aug 22-24
> needs more people as well.
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