13

For most backcountry navigation I use a topo map and compass when necessary. Generally I'm following known trails and combined with some basic awareness of cardinal direction and land features I don't really need electronics.

This fall, I'm going to a large desert that's fairly off the beaten track with little in the way of established trails. There are some features I'd like to be dead-accurate on (water sources, primarily) so that when I find them I'll be able to accurately record their position for future use.

I'm trying to decide between my phone, a Samsung Galaxy S5, or a dedicated GPS receiver (Garmin, etc). GPS receivers seem a bit more bullet proof, seem to have a more stable operating system, and as a dedicated device probably have better battery life.

What would be the main reasons why someone would pick one versus the other?

Also, I have a 16K mAh Anker battery, but given the weight (~11oz) I'd prefer to not lug it around if possible.

  • Somehow related: outdoors.stackexchange.com/questions/1260/… – Benedikt Bauer Jun 7 '15 at 16:20
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    "16K mAh" took me a second to parse, shouldn't it be just "16Ah"? – Shelvacu Jun 8 '15 at 3:45
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    @shelvacu if you're talking pure electrical land, yes, but batteries in that range generally have their amperage expressed in mA. – Eric Jun 8 '15 at 3:47
  • If you're seriously considering going for the phone test it in the wild in flight mode (unless that disables your GPS). Not just against AGPS issues (see below) but phone/app quirks. Also to get an idea of the battery life in GPS-only use. – Chris H Jun 8 '15 at 13:18
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    I'm guess you know this already, but for completeness sake: you should never entrust all of your navigation to electronic devices, especially in regions where getting lost can be quite dangerous for you. Map and compass should always be carried as a backup. – fgysin Apr 20 '16 at 6:20
16

Most GPS receivers in phones do not work nearly as well as stand-alone GPS devices. Usually, one wouldn't notice this because phones use assisted GPS where they get the orbital data and/or almanac of the GPS satellites as well as the exact time from the GSM network. Also, they have an approximate position of the device. Without that data, phones are very slow getting the position. Usually it works okay if there is still AGPS data downloaded, but that data goes stale after a few days.

Downloading the full almanac data from one satellite takes 12½ minutes.

Some phones I used instantly forgot the data sent by the satellites after closing the app using GPS. This means another 12½ minute wait on the next usage.

Standalone devices are optimized for that situation. While some of them can also use AGPS data, they are expected to work without it. No such device will, for example, "forget" the almanac and expect it to be downloaded from the internet.

I have a fairly recent Sony Xperia Z3 phone at the moment which can use Glonass satellites in addition to GPS but without Internet, a ~5 year old i-Blue 747A+ beats it by far. Faster fixes and more accurate position. If you insist on using your phone (or want it as a backup) I suggest you buy a Bluetooth GPS tracker/mouse and use that with your phone. On Android, there are apps to use the GPS position via Bluetooth instead of the built in receiver.

You can test how well your Galaxy S5 works by downloading the GPS Status & Toolbox app, disable all data connections (Wifi and mobile), reset the AGPS data using that app, restart the phone and then get the GPS position. You will notice that it is very slow. After the phone got a first fix, try to close all apps using GPS, wait a few minutes and try to get the position again. Do the same but restart the phone. This should give you a realistic estimation of how well your phone will serve you in the desert.

17

I think you already answered your own question. Most dedicated GPS devices are more rugged, have better battery life, and don't require a data connection to work well. A phone has a lot of power overhead and is fragile.

There are a few possible advantages to a phone. If you're already going to be carrying one, it reduces the total weight required. It's often easier to update data on a phone than on a GPS device. On the other hand, there aren't in my experience very many good apps for phones which have full-featured GPS capabilities without a data connection. Most of the GPS type apps I've tried I've been unimpressed with, and would've preferred a dedicated GPS device.

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    If you have the space a phone makes a good emergency back up to a GPS anyway :) – Aravona Jun 7 '15 at 20:12
  • +1: There are several apps that are 'good enuf' if all you want is basic features such as tracks, waypoints and directions or route following. Problem is most try too hard and fail to get the the basics right, and finding the better ones is a needle in a haystack problem. – user5330 Jun 7 '15 at 21:33
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Let's go through the different aspects of phone versus dedicated GPS device point by point (however, quite surely without being complete). Basically you have to decide which points apply in your situation and how you weigh them.

GPS reception and accuracy

When the first smartphones with GPS units hit the market, there was the saying that their GPS positioning was less precise than that of dedicated GPS devices. The technical rationale given for this is that the GPS antenna of a smartphone has to be mounted hidden somewhere within the phone's body where it might not have optimal reception. In contrast dedicated devices have an antenna that is positioned in an optimal way, even if that means that the antenna sticks out a bit. However, that does not mean that the GPS accuracy in a smartphone is necessarily worse than a dedicated one, as for example this test has shown. State-of-the-art smartphones, especially the higher end ones, are in principle able to play in the same league with dedicated devices.

But there are two possible drawbacks due to the internal antenna:

  • The reception depends more strongly on the orientation of the device with respect to the sky, i.e. accuracy might worsen a bit if you just throw your phone into your backpack and it rests there in a way that the GPS antenna is shielded towards the sky by all the electronics, the battery and parts of the case. When held in hand, there should not necessarily be a difference.

  • Basically the same limitation occurs if the device is used in conditions where the sky is to some extent shielded by the environment – imagine being in a thick forest, maybe additionally in rainy weather with all the trees full of wet leaves or in a deep valley with not much open sky above you.

Battery life and endurance

Here the dedicated device is clearly in favour, however, it depends on the use case, how big this advantage is.

If you use the device for full navigation and/or tracking, i.e. doing location updates and maybe having the display on all the time, your smartphone might easily only last for some hours, even with all unnecessary things (WiFi, Cell Connection etc.) turned off. Even if you just use your phone only to look up the location every now and then and keep GPS off the rest of the time, it might suck a lot of power just by having to run its operating system. There are lots of processes running on the phone all the time that will drain your battery even in standby. Turning the phone off when not needed would be impractical as well, because it will take some minutes to boot until it is ready to use and booting a full-blown smartphone can easily drain several percents of battery.

A dedicated device on the other hand has a very slim operating system that is not using much battery when idle and also does boot up quickly if you prefer to shut the device down if not needed. Above that, there are devices that run on standard AA or AAA batteries which makes it easy to bring some sets of spare batteries. Those give you quite surely more battery lifetime per weight for your dedicated device than a battery pack for smartphones and you can tailor the amount of batteries to take with you depending on the length of your trip.

Finally there's also some safety issue if you carry your phone also for emergency contact reasons: by draining your phones battery with GPS use you do not only lose your navigation but also your phone functionality.

Maps

If you want to have maps on your device, your mileage will vary with both devices. With a phone you can basically have every map that is available as long as you have cell coverage and many maps to be downloaded to the device if you have the right app installed. With a dedicated device it depends on what the manufacturer allows you to install on it and how easy it is to get additional maps for certain purposes like sailing, hunting or the like. This depends also strongly on the manufacturer or device.

Handling

Handling issues can be divided into software and hardware based ones:

Software

On a dedicated GPS you are basically limited to the software that the manufacturer has designed for the device and the functionality they give you. Hence it is important to have a look at your need and the provided functionality to chose a device that suits your needs.

With a phone on the other hand, you can basically get apps for everything, but not necessarily one that will bring all you need. Also as far as I see, there's some divide into small, slick apps that do only one or two certain tasks on the one hand and big, heavy ones at the other hand that provide a lot of functionality (which is mostly not needed for your use case), at the cost of higher battery drain.

Hardware

On the hardware side I see a clear advantage on the dedicated device for several reasons:

  • Most of them are more or less waterproof which is not only a matter of carrying them in humid weather or for tours around water but also for example when having them get moist in the pocket of your hardshell jacket or trousers on a sweaty ascent (yes, I know of people who have killed their smartphone that way). Also using them with dirty hands is no problem.
  • They are constructed for harsh environments with a rubber casing so they won't be damaged seriously if they get some scratches or fall out of your hand or pockets.
  • Most of them are designed to be usable with gloves, so no need to get your gloves off. This can be essential in cold winters but is also nice on bike trips where it's quite annoying to get off your gloves just to see how far you've already ridden.
  • Finally, and for me one of the most striking parts: have you ever tried to read something on your smartphone display on a summer noon in bright sunlight? You won't have any chance since the background illumination of the phone display is not strong enough to outshine the sunlight. Most GPS devices have instead transflective displays that use the ambient light instead of a backlight and stay readable in the brightest sunlight. They have a backlight as well, however this is only needed for low light situations and thus saves you battery time.

Conclusion

Basically you have to decide yourself and I hope to have given you the most important properties to influence your decision. If the device is somehow part of your survival plan (this is what your question sounds like) then I for myself would go for a dedicated device since the smartphone solution appears to have many more modes of unwanted and unexpected failure.

8

I use Timble GPS Hunt Pro on my Samsung Galaxy S5 phone. You can download topo, BLM boundaries, private property and other types of maps that work just fine without a cell signal. The maps I use are incredibly detailed. If you do have cell coverage, you can add weather overlays. Map prices are reasonable, and you can buy a subscription that lets you download as many maps as you like.

I turned off most of the power draining features on my phone and got reasonably acceptable battery life. I did have to recharge the phone back at camp. I would imagine a 1.6 Ah battery would last for quite a while, as long as you don't run the phone's screen a lot and shut off all the non-essential stuff (WiFi, NFC, Bluetooth...).

I use an Otterbox case on my S5. Almost bullet proof.

7

For your situation I strongly advice against relying on your phone. It's a great backup but to much of a risk to use as a main device.

Three reasons to get a dedicated gps:

  • Batteries: A gps mostly works on standard AA batteries which can be bought anywhere and rechargeable ones are easily charged on solar energy. (look up goal-zero for instance).
  • Rugged: Yes you can put your phone in a case... but devices like the Garmin gpsmap devices are water and dust proof on their own, and they can stand up to some physical abuse.
  • Offline: Yes, also something your phone could do. but a dedicated gps device is made to work offline and will in no case accidentally delete your files because it couldn't find your license key or something like that (I had it happen with some marine map apps).

Next you'll need to choose what type of gps you want.
(Please note that my preferred brand just is garmin, there are probably loads of other devices).
If you'll only be going out trekking once or twice you probably don't want to spend to much on a device.
Get one that just does the basic trekking and point to point navigation, you can load your waypoints/routes from your computer before you leave.
Check out the Garmin eTrex for example.

If you're going out a lot then go spend some more.. The battery life will be a bit shorter with every big feature added but not to much.
First of a device with an actual detailed map is great, use (free!) open source maps from open-streetmap and you even get all the small bushtrails.
Colour screen is a nice addition for better orientation by map.
Other features like a 3-axis compass and glonass/waas support are also a plus for better precision (even get's you point and shoot compass navigation).
I have a Garmin gpsmap 64s myself, I use open source maps for street, trail and even nautical navigation.
Battery life is mostly about 20 hours when I use it in a battery saving mode (just checking the map every now and then but still tracking).

1

It is also worth mentioning that there are other ways to obtain absolute position references by using astronomical observations. Most of these are centuries old and of course, are not anywhere near as convenient and in most cases not as accurate a GPS however they do have the advantage that they don't depend on electronics or batteries to work. The modern traveller also has the advantage that watches are now very cheap and reliable as accurate time measurement was a major obstacle to astronomical navigation for a long time.

In most cases these methods are, in practice, rendered obsolete by GPS but at least trying the out might add an extra element of interest to a desert trip especially with some historical research beforehand to put them into context.

Similarly it is always worth doing at least a bit of research into alternative methods of navigation in a new environment as, again, they add an extra layer of interest an immersion to a journey and could make all the difference in an emergency.

1

Seems to be a lot of bad/obsolete info on this thread.

I've been using my Android phone for Backcountry navigation for 5 plus years now. I use an app that lets me create an offline map and I put the phone in airplane mode when I'm in the wilderness. My battery lasts two and a half days before I have to recharge it, which is easy to do with a solar charger or a backup battery.

And by the way, what Google calls "high accuracy mode" is simply a trick to get you to share all of your data with them. It is proven to be less accurate for location than the GPS alone. And the GPS in your phone probably has access to Satellites that a stand-alone GPS does not have access to, such as Russian GPS satellites. So your phone is going to be at least as accurate as any Standalone device and probably more accurate. Not to mention when you create an offline map you're getting the latest map data, not something that's two or three years old or however long it's been since you updated the maps in your stand alone GPS device. So the only real advantage of a standalone GPS device is the supposed ruggedness. But if you actually check these things out, many of them aren't waterproof anyway. Plus, they have smaller screens, lower quality graphics, and less features than a good Wilderness app. I personally use MyTrails, but there are others out there if you want to pay for them.

Just remember, whether you're using a standalone GPS or your phone for your GPS, that electronic device can and will probably fail someday. You should always bring a paper map and a compass, and learn how to use them!

1

The GPS receiver in recent tablets and phones is actually quite good.

I use a Nexus 7 Android tablet for outdoor navigation, and it works very well. Tablets generally allow you to shut things down more than phones. A phone may always be looking for a cell signal, for example, and thereby wasting power.

I use a app called Backcountry Navigator, but surely there are a number of apps out there that do similar things. The point of these apps is to allow you to download maps ahead of time. Then when you're outside, the tablet doesn't need any external connection, like cell service or WiFi. In fact, you shut those off to conserve power.

I've been quite impressed by the GPS in my Nexus 7 tablet. It actually seems to be better, and is certainly easier to use, then dedicated GPS units only a few years older.

The main advantage of the tablet is the decent screen. That allows you to see enough of a map at useful detail at one time. I have found that the battery is easily enough for a all-day hike. I keep the GPS running all the time, with the BCNAV app recording the trail, but the screen off. I only turn the screen on for short periods of time when I want to look at the map. Otherwise, the tablet is in my pocket and does a remarkably good job of tracking location even though the antenna is right up against my body. This uses up about half the battery on a "all day" day hike.

Not all tablets are equal. I once used a tablet that was "free" due to some promotion by Verizon. It was terrible at tracking while in the same pocket. It also charged much slower when back in the car. Battery life wasn't as good, and it was impossible to turn off the cell radio.

Having a tablet that has a wide area map at multiple detail levels, a GPS to show you where you are, and a app to show you the track you have been on is definitely nicer than a paper map and compass. However, in a serious situation, like needing to find water spots in the desert, I wouldn't rely on it as the only navigational aid. In that case, I'd bring a map and compass as a backup.

If you're going out for several days, then don't leave the tablet on all the time recording your track. You can live without that. The battery of a decent tablet will last many days if you only turn it on occasionally to look at the map and get a GPS fix.

Another possibility, especially since you mentioned the desert, is to bring a solar charger. These can be small and light. A 20 to 25 square inch panel should provide enough power to greatly extend battery life, if not top it off occasionally. You can strap it to your pack and charge the tablet while hiking.

You can also get a panel with a rechargeable battery built in. The panel charges it's battery separately, then the battery can be used to charge the tablet later, even when there is no sun. One extra lithium 18650 cell doesn't really weigh that much or take much space.

  • +1 and a I would have given an extra if I could, as you have several separate good points. – Willeke Apr 2 '18 at 12:05

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