[pct-l] smartphone as GPS

Mon Oct 25 15:32:21 CDT 2010

I'm taking an iPhone on my thru next year. I've been evaluating various
offerings, and I think I'm going to use MotionX's product. Loading the
waypoints/tracks require emailing them, but it's not a large amount of data,
so you only have to do it once for the entire trail.

It allows you to download map data for use when there is no network like
many other apps, but I like this one because I have more control over what
data I download. I can control the zoom levels, ie what I see when zoomed
way in or way out. It also has a unique, afaik, offering about how to select
the region. It allows you to center a circle over an area and choose the
radius like all the apps, but it also lets you download the data along a
route. You can choose how far to either side of the "route" you want detail
for. So far I've only done this by selecting a start and end, so I get a
long rounded rectangle area of detail data. I'm still not 100% sure I can
use an actual "route" or track to define the area to download. Even if I
can't, being able to select segments will help minimize the storage space
needed for each leg. As an example, I downloaded the area from Flagstaff to
the Grand Canyon that covers a ride I did weekend before last. It covers an
area ~70 miles long and 20 miles wide. I selected a starting zoom level
about half way through the range, and an ending zoom to the most detail.
Zoomed all the way out, this data shows ~50 miles or so total. Zoomed all
the way in, the entire screen covers only ~600 yards. This seems like it
will work well for me. All this offline data only requires 170MB. I estimate
each section of the PCT should require less than 1GB. The though just
occurred to me to test this. I'll respond again after I download a couple
sections and let everyone know how much data it requires.

With tremendous respect and gratitude to halfmile, I didn't care for the map
app he recommends. It looks like it only has USGS topo data. There is
another app that uses the same, or similar, data. The PCT isn't even listed.
I also don't see any support for tracks or routes. There was no trial, so I
was reluctant to spend $8 on something I may not find useful. Out of
fairness, and because of halfmile's endorsement, I went ahead and downloaded
it today. I'll play with it and provide feedback when I update about data
useage with MotionX.

On Mon, Oct 25, 2010 at 11:10 AM, Halfmile <list at lon.net> wrote:

> John,
> For the iphone I think the two best apps are Topomaps and Basic GPS.
>
> http://topomapsapp.com/
> http://www.basicgps.net/Basic_GPS/Main.html
>
> Both work well in areas without cell service and are accurate to
> better than 50 feet in my testing. You need to preload maps into
> Topomaps (best to use wifi) and it can download waypoints directly
> from my site at www.pctmap.net. Basic GPS only displays your location
> in UTM coordinates, so you would use this app with maps that have UTM
> grids printed on them. This is simple and works well and you can
> easily plot your location on a map with 25 meter or better accuracy.
> Basic GPS saves your phone battery too since you turn the phone on,
> wait a minute or two for the GPS fix, plot location, then turn the
> phone off. An iPhone will only run a few hours with the GPS on before
> it drains the battery.
>
> Last time I tried to use Motion X, I didn't find it very useful
> because it didn't work well preloading maps for areas without cell
> service and had limited waypoint storage capability. Maybe that's
> changed.
>
> -Halfmile
> www.pctmap.net
>
>
>
> On Mon, Oct 25, 2010 at 10:37 AM, John Abela
> <pacificcresttrail2011 at gmail.com> wrote:
> > @Jim K,
> >
> > Did you just use the pdf formats, or did you use the gpx waypoints and
> load
> > them up into MotionX, or some other method?
> >
> > Thanks,
> > John
> >
> >
> > On Mon, Oct 25, 2010 at 10:27 AM, Jim Keener ( J J ) <
> > pct2010 at ridgetrailhiker.com> wrote:
> >
> >> Greetings,
> >>
> >> If a device is marketed as having "GPS", it will have satellite location
> >> capability. Smartphone GPS is typically not as accurate as dedicated GPS
> >> devices.
> >>
> >> Many, many hikers have completed  the PCT without any GPS capability. I
> >> carried an iPhone 3Gs this year and, using Halfmile's waypoints, located
> >> myself any time I wanted. There is some really good GPS software
> available
> >> for almost all smartphones.
> >>
> >> Walk well,
> >> Jim Keener ( J J )
> >>
> >> On Oct 25, 2010, at 10:11 AM, "greg mushial" <gmushial at gmdr.com> wrote:
> >>
> >> >> Message: 2
> >> >> Date: Mon, 25 Oct 2010 08:44:13 -0700
> >> >> From: Austin Williams <austinwilliams123 at gmail.com>
> >> >> Subject: Re: [pct-l] smartphone as GPS
> >> >> To: pct-l at backcountry.net
> >> >> Message-ID:
> >> >> <AANLkTinOvNfuQPZHGGwxJk2BCWN9RR=DTjKCx7wJ9yr6 at mail.gmail.com>
> >> >> Content-Type: text/plain; charset=ISO-8859-1
> >> >>
> >> >> Be careful.  Most of the time the 'GPS' in smart phones is based on
> >> >> cell-tower triangulation, NOT gps-satellite triangulation.  That
> means
> >> >> when
> >> >> there are now cell towers around, the "GPS" on the phone won't work.
> >>  Make
> >> >> sure you buy one that uses *real* gps, not the kind that uses cell
> tower
> >> >> triangulation.
> >> >>
> >> >> Just a heads up.
> >> >>
> >> >> --
> >> >> Austin Williams
> >> >>
> >> >
> >> > Is there any (published) indication of accuracy difference? Seems that
> >> since
> >> > generally towers don't jump around, they should be as good as
> >> satellites...
> >> > no?
> >> > TheDuck
> >> >
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