[pct-l] GPS?

Thu Feb 7 20:37:31 CST 2013

Concerning Assisted GPS, from what I understand the data it downloads is good for roughly a week or so of use.  So when you are in town and have good data signal on your phone, just use any GPS app once to refresh the aGPS cache.  For the next week or so, even on airplane mode with no data signal to help, your TTF (time-to-fix) should be significantly lower than if you had no aGPS data to help get a fix.  Wikipedia has some good info on Assisted GPS if you want to learn more.

I used my smartphone successfully a few times to find the trail this past year on my PCT thru-hike.  It was never truly necessary, but definitely cut down some time when unsure of where I was and where the trail was.  In a heavy snow year, I might consider a standalone GPS, but if you use a topo-enabled app on your smartphone and keep the aGPS updated, it won't be that much worse than a standalone GPS I think.

InsGadget

Sent from my Windows Phone
________________________________
From: Fred Walters<mailto:fredwalters2 at gmail.com>
Sent: ‎2/‎7/‎2013 6:04 AM
To: pct-l at backcountry.net<mailto:pct-l at backcountry.net>
Subject: Re: [pct-l] GPS?

I have the impression that many carry smartphones (iPhones/Androids)
virtually all of which include GPS (aGPS).  I would do the same as much for
the town connectivity/phone/music as for the GPS.

However, do the GPSs in these devices need a data connection (Wi-Fi or
cellular) ?  As I understand it aGPSs can operate in different ways, some
just using the data connection to download new aGPS data for a faster fix
(every few days), but the GPS will still work without such data but taking
longer to get a fix (MSB mode).  Others need the data connection to pass
GPS signals to a aGPS server which processes them and returns the fix (MSA
mode).  So does anybody know if the phone the aGPSs will operate as
straight GPSs (i.e. without the "a").

Background: seems that for an occasional backup assistance, the GPS in a
smartphone does not mean extra weight,  and might still help, all be it
with limitations (e.g. limited battery life).

Fred

On Thu, Feb 7, 2013 at 8:28 AM, Ned Tibbits <ned at mountaineducation.org>wrote:

> As Mango illustrates through his experiences along the trail, even when
> following tracks of others in the snow ahead of them, it is easy to get
> "off-track" and waste a lot of time wandering around looking for it.
>
> Unless you are sufficiently far enough back in the herd to have a clear and
> deep trough to follow, a lot of the people in the forefront wander a bit
> while hiking over snow in the general direction they think they're to go.
>
> The problem through the sierra is that below timberline, when you're hiking
> through dense or even sparse trees, the trees block your view of high
> landmarks by which you need to navigate, so it can be really easy to get
> turned around or at least head up the wrong canyon or creek fork.
>
> Yes, a topo along with a keen awareness of your surroundings can get you
> where you want to go over snow, but you need to know how to "read" the
> topo,
> translating the one-dimension on paper to compare it to the three-dimension
> in front of you and you need to be attentive to the geography around you.
> If
> you're too busy talking in a group or just flying along not paying much
> attention, it is very easy to become "temporarily misplaced."
>
> Above timberline, as many have said, it is easier to navigate by
> line-of-sight because you can see those high landmarks, peaks, and passes,
> identify they with the topo, and simply head toward them.
>
> The need for the GPS comes in handy, therefore, down in the trees. Now,
> even
> when you're truckin' right along from Pass to Pass, mostly above
> timberline,
> between those passes your route will descend down into the trees, then
> further down to some big creek that you'll have to wade through, only to
> abruptly ascend back up through trees to snowline again. It is down in
> these
> tree-filled creek drainages that most folks get lost for a period of time.
> This is where the GPS rules. And the trees only become more numerous as
> your
> average elevation drops the further north you go, so if you think you can
> get by without one in the sierra, you may still need one the closer you get
> to Tahoe.
>
> I'll never forget the day just south of Richardson Lake on the PCT/TRT west
> of Tahoe two years ago when three PCT thru hikers flew by Lady J and I as
> we
> were following the trail on 6 to 8 feet of snow (in late June). We were
> navigating through dense trees while traversing along a broad ridge, we
> couldn't see more than 80 feet in front of us, we had our GPS out so we
> could "see" whether the trail was to our right or left, we couldn't move
> very fast because of these situations, and we could hear these guys coming
> up through the forest behind us, crashing through branches as they came,
>
> They needed to make the miles, so they were in a hurry. We talked briefly
> when they met us, but they didn't have it in them to stop for long. So, off
> they went, first the leader, then the followers. First they went along the
> traverse, then turned right and went toward the ridgeline. The trail didn't
> go that way, but they did. Pretty soon they came back toward us searching
> for the route, only to bisect it and drop below the trail. Pretty soon they
> came back up the slope and crossed the "trail" again and headed back up to
> the ridge. We never saw their tracks again even though we deliberately
> stayed on top of the summer trail (we were practicing how to do this) for
> the next several days!
>
> There are several lessons to be learned from all this,
> - people wander when trying to figure out where the trail is when beneath
> snow.
> - haste burns a lot of energy and isn't worth it when snow-hiking.
> - the old adage still applies, "Go slow to go fast."
> - a GPS unit is invaluable for knowing where you are in relation to where
> the trail is when in trees.
> - know how to "read" a topo map and compare what it's telling you about
> your
> surroundings to what you see in front of you.
> - yes, any electronic device can fail, so don't solely rely on it. You can
> get through the woods on snow without one, but it takes a lot more savvy,
> experience, and training.
>
>
> Ned Tibbits, Director
> Mountain Education
> www.mountaineducation.org
> -----Original Message-----
> From: Jim & Jane Moody
> Sent: Wednesday, February 06, 2013 5:30 PM
> To: pct-l at backcountry.net
> Subject: Re: [pct-l] GPS?
>
>
>
> Daniel,
>
> Like a lot of questions, the answer is "it depends".  If you are
> thru-hiking
> nobo with the herd, you probably won't need one, since by the time you get
> into the Sierra, you'll probably be with a group, one of whom might have a
> GPS.  Also, the less snow in the Sierra, the less likely you are to need
> one.
>
>
>
> However, if you are starting very early, going sobo, going alone, and/or
> sectioning in front of the herd in a heavy snow year,  then a GPS will come
> in handy.  I didn't take one in 2010 (thru-hike attempt), but it would have
> saved some time in the Sierra.  Our "team" of 5 had 3 different sets of
> maps, a couple of compasses, and one GPS, which almost never got used.
> However, due to Shroomer getting us lost almost daily, we really should
> have
> used the GPS more often to save time spent zig-zagging, backtracking, and
> heading up the wrong ravine. (Just kidding, Shroomer).
>
>
>
> In 2011 I started WAY TOO EARLY at Sonora Pass and spent the equivalent of
> several days trying to navigate with just a map & compass.  Many times I
> was
> frustrated and disheartened by not knowing where I was or where the trail
> was, so a GPS would have been wonderful.  In 2012 I started north from
> Chester in late July and had no navigation problems at all.  I did,
> however,
> carry a GPS with Halfmile's maps, tracks, a nd waypoints on it, which gave
> me a great feeling of confidence (I also carried map & compass).  I used
> the
> GPS frequently  to confirm what I already knew and to get practice in using
> it.
>
>
>
> For me, I will be carrying one every time I'm on the PCT.  It's kinda like
> a
> first aid kit - you hope you don't need it at all, but if you need it, you
> REALLY n e ed it.  And if you get one, be sure to load Halfmile's maps,
> tracks, and waypoints.  As an alternative, y ou might try the cheapest (and
> lightest) model that only gives location in UTM coordinates , which can be
> used to determine your location on your paper map.
>
>
>
> Good luck,
>
> Mango
>
>
>
>
>
>
>
> ----- Original Message -----
>
>
> From: "Daniel Salazar" <techtravel7 at gmail.com>
> To: pct-l at backcountry.net
> Sent: Wednesday, February 6, 2013 5:47:36 PM
> Subject: [pct-l] GPS?
>
> Is it necessary to have a GPS on the trail or is it just extra?
> _______________________________________________
> Pct-L mailing list
> Pct-L at backcountry.net
> To unsubcribe, or change options visit:
> http://mailman.backcountry.net/mailman/listinfo/pct-l
>
> List Archives:
> http://mailman.backcountry.net/pipermail/pct-l/
> All content is copyrighted by the respective authors.
> Reproduction is prohibited without express permission.
> _______________________________________________
> Pct-L mailing list
> Pct-L at backcountry.net
> To unsubcribe, or change options visit:
> http://mailman.backcountry.net/mailman/listinfo/pct-l
>
> List Archives:
> http://mailman.backcountry.net/pipermail/pct-l/
> All content is copyrighted by the respective authors.
> Reproduction is prohibited without express permission.
>
> _______________________________________________
> Pct-L mailing list
> Pct-L at backcountry.net
> To unsubcribe, or change options visit:
> http://mailman.backcountry.net/mailman/listinfo/pct-l
>
> List Archives:
> http://mailman.backcountry.net/pipermail/pct-l/
> All content is copyrighted by the respective authors.
> Reproduction is prohibited without express permission.
>
_______________________________________________
Pct-L mailing list
Pct-L at backcountry.net
To unsubcribe, or change options visit:
http://mailman.backcountry.net/mailman/listinfo/pct-l

List Archives:
http://mailman.backcountry.net/pipermail/pct-l/
All content is copyrighted by the respective authors.
Reproduction is prohibited without express permission.