GPS recommendation

Check out the Backcountry Navigator Android app. I've decided to give it a try instead of getting a new GPS-only device. The app on my phone suits my needs (marking waypoints and checking location, only occasionally). plus it has full res topo maps.

Try the demo (30 day trial?) and see if it works for you.

If your needs/wants for things like compass/altimeter and the number of tracks & waypoints are low, then any handheld Garmin unit would probably work just fine.

You might consider the new Garmin eTrex 10, 20, 30. They are just being released so you may have to wait a week but what you'll get is a small gps that not only tracks the US GPS system but also the Russian GLONASS system as well. Up to 12 US satellites + 24 GLONASS satellites tracked simultaneously. This combination "should" be a little more accurate and give you tracking in the most challenging conditions. You'll begin to see this new combination chip showing up in smartphones later this year.

I have and use BackCountry Navigator with an android phone. Works great and is a good alternative to a stand alone GPS however battery life is limited.

Good luck.

"This combination "should" be a little more accurate and give you tracking in the most challenging conditions. "

There is absolutely no proof of this assertion at all.

GLONASS has been in trouble ever since the Russians let the system deteriorate years ago.

–B.G.–

@Bob

That's because it's more about processing the data instead of the data itself right? What about the belief that it should track under more situations?

RE:"challenging conditions":

http://www.pcmag.com/article2/0,2817,2392569,00.asp#fbid=X6ojV5k3fkQ

Accuracy increase is anecdotal comments from people who use both systems in precision survey work. I'll try to hunt up some references.

Russian GLONASS was optimized for the old Soviet Union's geography. To a certain extent, it is at a higher latitude than an average spot on Earth. The GLONASS satellites fly on a different higher angle with respect to the Equator to maintain that optimization (as compared to GPS).

If you were located on some ice floe at 70 or 80 degrees North, then I think GLONASS+GPS might get you some slight advantage over GPS alone. As soon as you locate into the normal latitudes, that slight advantage is lost.

The G in GPS is for Global.

–B.G.–

+1 on Backcountry Navigator. You already got the hardware and the app itself is cheap. If it suits your needs your golden.

not too intuitive….I like the idea, and using my Droid would be great for photos, video, and gps…but so far I am not too impressed

Thanks everyone.

For GPS. I know maps of different countries/areas can be bought. How about the map quality and price between major brands (Garmin as far as I know). Another question is which brand has most maps available? I may travel to Europe and Asia (Nepal, India, China), maybe more I hope…

Backcountry Navigator seems interesting, I am gonna give it a try. Does it also need to buy maps like a GPS?

Cheers.

Don't put too much faith in the GPS systems. They are nice for approximate coordinates, but vary widely in accuracy – dependent on conditions (even within the same unit)

We just spent the entire spring and summer fine tuning our backwoods search and rescue skills. We had three different units – garmin, magellan, delorme all in the $300 – $600 range. We usually had at least 9 locked satellites and the coordinates varied greatly. (try this – sit down for lunch with your unit on and look at you wild movements when you get up) We ended up using the gps for aproox locations of our search lanes and honing our compass and map skills for the actual searching.

Remember to learn the old ways. Gps is just a tool. Unless you get into the surveyors price range ($5000), then expect some errors.

Enjoy,

Dave

To see GPS accuracy in action, you only have to do a "there and back" dayhike with the GPS tracking on. Much of the time the outbound and return tracks will overlap, sometimes they will be separated by 20-30 yds, occasionally more, even tho' you walked the exact same route.

Still, thats a lot better than most can do with a map and compass in low visibility.

As an exercise, I sometimes navigate off-trail using map and compass in low visibility and later compare the GPS track of where I actually went to where I intended going (inaccuracy due to tree cover is a non-issue for me).

For the OP: I use a Garmin Dakota which does everything I could possibly want.

@Bob:

We use survey-quality GPS equipment in our business, which is located in the south-central USA, far from the Soviet block of countries. Some of this equipment is single-constellation equipment (GPS only), and some of it is dual-constellation equipment (GPS and GLONASS). From personal experience, I can tell you that our dual-constellation equipment works much better than the single-constellation equipment.

The accuracy of the equipment varies as the satellites move relative to the survey point and to each other. There are periods of time where the single-constellation equipment simply doesn't work, while the dual-constellation equipment continues to operate. We have construction equipment that is controlled by the GPS equipment, and until we upgraded it all to dual-constellation systems, we would occasionally have to park it until the satellites aligned. Now, we get a full 8 hour day out of the equipment. As you can imagine, the effect of parking equipment on the business' bottom line is dramatic.

I have no idea if this value will translate to the consumer products, but GLONASS is not the useless system you make it out to be. I've experienced the value many, many times!

Scott

@Dave:

I agree wholeheartedly that one should learn map-and-compass navigation before relying on GPS. However, I disagree just as vehemently with your statement that GPS position data varies "widely in accuracy".

I've been a map-and-compass user, as well as a GPS user, for over 15 years. In that time, I've used Garmin, Magellan, and Delorme consumer units, as well as TopCon survey units. In that time, Selective Availability has been turned off, and that improved position accuracy on consumer units considerably.

You are correct that a consumer unit's position will vary when you are standing still. When this happens, you're seeing the accuracy of the system right before your eyes. However, this accuracy is still far better than what an expert can do with map-and-compass! If you took an expert in map-and-compass and pitted them against an intermediate-level GPS user in a contest to race from Point A to Point B off-trail, the GPS user will almost always arrive at Point B sooner, especially if the coordinates of Point A are unknown to either contestant at the start of the event (simulating being lost).

You mention that you just spent some time practicing your GPS skills for SAR practice and that your positions varied greatly. I would suspect that if your positions varied more than about 30m, then you had a different datum set on the units. Every GPS has a setup page where the datum can be set. The three most common in the USA are NAD29, NAD83, and WGS84. WGS84 is very similar to NAD83 (comparing one to the other rarely shows a measurable difference). If all GPS users are not using the same datum, you'll get varying coordinates. This is only a problem when trying to compare one unit to the other. It is also important to make sure that your map datum matches your GPS datum if you are using a map with the GPS coordinates. I apologize if you're already aware of the datum mis-match issue. I couldn't tell from your post.

To say that GPS should be avoided because it is inaccurate is simply wrong. GPS is absolutely more accurate, as well as more convenient, than cross-country map-and-compass navigation. There's a reason why surveyor's use it, ships use it, and there's a reason air traffic control is contemplating a switch to it.

Again, I would tell someone that if their life depends upon their ability to navigate, they need to understand and practice map-and-compass navigation before diving into GPS navigation. At the same time, I wouldn't tell someone to avoid GPS due to any inherent inaccuracies.

Regards,
Scott

Scott,

My point was not to steer anyone away from a GPS unit. I re-read my post and I didn't see that I said that a gps should be avoided. It was to teach them that it is a tool and the consumer units are not as accurate as you may think. People get a false sense of security from these units and are unprepared if something goes wrong – (batteries, unit failure). You still need to know how to read a map and how to navigate.

Our GPS units were set to the correct datum and 1:24000 maps were loaded. The error rate was not related to any specific brand. We needed more accuracy than we were getting, as we were running lanes through thick bush. We were pushing the limits of these gps units. Even a 10m variance was too much for our needs. When we switched to using a compass and checked our track logs – the line was much more accurate. GPS units were fine for coarse searching. (50m or 100m lanes) Since we are a volunteer organization, we could not afford the more accurate units that a surveyor would use. It very well could be the canopy that we were working in. For trail walking they would have been fine.

I realize that the Gps system in general can be very accurate; I just don't believe that on a consumer level it is there yet. They will get you back to your car; you may just have to walk side to side more.

Sorry for the miscommunication.

Dave

David:

Thanks for the further explanation. GPS definitely has its limits, and it sounds like you've found them. As you said, it'll get you back to your car, which is adequate for most recreational users. I don't think that a survey-quality GPS system would have worked for your use. Heavy cover kills the accuracy of survey units even more so than with consumer units. Surveyors switch to optical instruments (called a total station) in heavy cover.

Incidentally, survey GPS units probably don't see much use in mountainous or heavy-cover areas because they rely on a radio or cell-phone signal in order to get their corrections, in addition to the satellite signals. In heavy cover, the satellite signals don't come through, and in mountainous regions, the radio or cell-phone signals don't come through.

I think you're pretty well stuck with compass-and-map for your SAR work…

Scott

"I have no idea if this value will translate to the consumer products, but GLONASS is not the useless system you make it out to be."

Scott, I didn't say that and I never used the word "useless."

I said that the GLONASS system has been in trouble for a long time. For too many years, the Russians could not afford to keep the system up, and its availability and accuracy got bad. Now that they have a few more rubles to spend, they've been fixing it up again. However, it still is not back to 100% in terms of availability.

–B.G.–

One big reason why Scott gets good results and others get mixed results has to do with the antenna.

On big equipment you can afford to have a big antenna, typically amplified, that is on some kind of a post sticking up high above the ground. That gets good results. If you have some pocket-sized consumer receiver and you are using only an internal patch antenna, that is not the way to get good results. Further, lots of consumer receivers don't even have an antenna port. When you are holding a consumer receiver at waist level, your upper torso is often blocking lots of view of the sky, and that further worsens results.

I've installed lots of systems with remote amplified antennas, some as much as 500 feet away, so I know how much a good antenna can help.

–B.G.–

i found this article most interesting … it is GPS related … somewhat anyways … maybe GPS standalones will be more accurate than the ones on PLBs ….

http://blog.oplopanax.ca/2011/08/personal-locator-beacons-from-rescuers.html

Technology
In the heat of the search it is easy to believe that a position reported using an advanced system such as SARSAT would be accurate. However, reading about the system informs us that this is not the case. The satellite-based location fix is obtained from the 5 watt, 406MHz radio signal alone, and not using a GPS. It is accurate to about 5 km. This is the default operation of the PLB system.

If the transmitting device is also equipped with a GPS, which is optional, it can “piggyback” the GPS-derived coordinates in the radio signal. The accuracy of this fix depends on many factors: the weather, the tree canopy, the visibility of the GPS satellites based on the local terrain and their current orbit, and the hardware used to calculate the position. In addition, the amount of data that can be transmitted by the distress beacon, or bandwidth, is limited, so the precision of the GPS fix is truncated. This results in a best-case scenario of +/- 125m for the most accurate fix possible under clear conditions.

Also remember that once the PLB is activated, SAR will be attempting to find you, and rescue you, but this takes time. In this case it took just over 24 hours from the time the PLB was activated until the subjects were extracted. Weather, terrain, and many other factors can effect the speed of the response.

@Scott
"If you took an expert in map-and-compass and pitted them against an intermediate-level GPS user in a contest to race from Point A to Point B off-trail, the GPS user will almost always arrive at Point B sooner, especially if the coordinates of Point A are unknown to either contestant at the start of the event"

Sorry, but that is utter bull. I have competed in mountain orienteering competitions (LAMM) where you race from point to point off-trail, navigating using map (unseen until the start) and compass and the good guys can navigate with pinpoint accuracy faster than I can run on the flat, even in thick cloud.

Nian,

Sorry for the digression in the above discussions. Does the backcountry navigator work if there is no cell phone reception? If no, then you may need to buy a gps unit. I would check what unit supports international maps and what the scale of the maps are. Are the maps on micro sd chips, or are they downloadable to a computer. Can you manipulate and print them or are they static? I would not recommend a touch screen unit. We spent a lot of time waiting for people to find their screens after a series of "butt dialing" and erroneous waypoints added.

Good luck,

Dave

P.S. I would still carry a set of waterproofed maps and compass with known locations and catching features marked.

gps has its issues,but they are relatively minor. OF course you should always know where you are, and how to navigate another way in case it fails.

Once, I lost the overgrown trail I had used while coming out of woods after sundown when deer hunting, and had to just tramp cross-country thru woods about 3/4 mile following my gps back to my ATV. Thru bushes, briars, standing water in drainages, etc. Just walk the direction it showed. I came out of woods that night close to 9pm on logging road about 30' from my ATV. Close enough.

Where navigation is critical, I like to have a GPS with spare batteries, and map and compass.

Basic navigational skills with map and compass are important, but in my opinion there is far too much bias in some quarters against the GPS. There are many situations where a GPS stands head and shoulders above map and compass. At night, for example, starting from an uncertain position. Or starting from an uncertain position in thick fog or in flat, thickly forested country. We can't always triangulate from distinctive peaks on nice, sunny days.

I like a mapping GPS.

Thanks everyone for your opinion. Just came back from a weekend hiking in Scotland. I tried Backcountry navigator, it's very nice. In fact I am living in UK, but I found this site pretty good with lots of information. So I asked the question here. I also tried another mobile based software called viewranger (http://www.viewranger.com/). This and Backcountry navigator are very similar. One can download map (need to pay of course) and use just like a GPS unit. I found these phone based software are enough for weekend hiking. I brought two batteries with my mobile so I don't worry about the power. And they are cheap. Compared with a GPS unit, one also need to buy different maps besides the cost of a GPS unit. But that doesn't mean I will use these mobile based software all the time. I may get a real GPS for serious multi-day hiking. And of course to develop some ability using compass and map. Thanks every one.