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Eric Blumensaadt
(Danepacker) - MLife

Locale: Mojave Desert
Most accurate handheld GPS? on 09/06/2011 12:41:32 MDT Print View

What is the most accurate handheld GPS for backpacking?

I'm not talking about battery-hungry professional GPS units.

Currently I have a Garmin Colorado 300 which seems "fairly" accurate
when it gets a good satellite constellation on its differential reception mode.

Is there anything better lately? i.e. better antennae, processors and software?

Edited by Danepacker on 09/06/2011 12:43:29 MDT.

Paul Hatfield
(clear_blue_skies) - F
GPS on 09/06/2011 15:05:24 MDT Print View

> Is there anything better lately?

Not really. IMHO, consumer-grade GPS receivers have not improved much in the last 5 years. If you want to spend a lot of money, you could get a Trimble GPS Pathfinder ProXT Receiver. Key features:

Real-time submeter GPS with integrated SBAS and EVEREST multipath rejection technology
50 cm accuracy after postprocessing with Trimble DeltaPhase technology
Receiver, antenna, and battery in one compact unit
Bluetooth wireless technology for totally cable-free operation
Rugged and weatherproof for all conditions
User-replaceable battery lasts a full day in the field

A lot of the accuracy is dependent upon post-processing in the software.

Paul Hatfield
(clear_blue_skies) - F
Clarification on 09/06/2011 16:01:51 MDT Print View

To clarify, the Trimble mentioned above needs to be connected to a computer/computing device in order to be useful. The computer should be running Windows in order to use the Trimble software, though GPS apps on iPhones, etc. may be able to connect to the receiver.

drowning in spam
(leaftye) - F

Locale: SoCal
Re: Clarification on 09/06/2011 16:23:33 MDT Print View

That's because of the extra processing to the raw gps data? That makes me wonder if these new tablets with gps antennas will soon have gps applications that can do the processing necessary to get accurate locations.

Jake Palmer
(jakep_82) - MLife

Locale: Pacific Northwest
Re: Most accurate handheld GPS? on 09/06/2011 16:46:56 MDT Print View

How accurate does it need to be? My Android phone with the Backcountry Navigator app and mytopo maps usually gets within 20 or 30 feet. That's plenty accurate for how I use it, but perhaps not for your application.

Steven McAllister
(brooklynkayak) - MLife

Locale: Atlantic North East
I Agree With Jake on 09/06/2011 17:29:53 MDT Print View

I agree, my Android phone with the Backcountry Navigator app and mytopo maps usually gets within 20 or 30 feet.

My old clunk GPS from many years ago was also plenty accurate for backpacking.

I don't understand why you would need more accuracy than that for backpacking, unless you are doing surveying or something else that requires precision.

Steven McAllister
(brooklynkayak) - MLife

Locale: Atlantic North East
P. S. on 09/06/2011 17:33:46 MDT Print View

I am not a heavy GPS user, but do use my Android on the trail from time to time, like when I have to take a detour or need to confirm a location when bushwhacking, or to find local restaurants, outfitters, motels, ...

I can go several days without recharge as long as I leave it in airplane mode most of the time.

Rick Dreher
(halfturbo) - MLife

Locale: Northernish California
Re: Most accurate handheld GPS? on 09/06/2011 17:37:40 MDT Print View

I suspect for most, sensitivity probably trumps accuracy, which is to say your ability to acquire and track a location in difficult conditions (forest cover, canyons) is more important than whether you know your location to one meter or just ten meters.

Newer units seem to have traded sensitive antennas for more channels and speedier processing. Whether that's a good thing I'll leave to the experts. What I see in field comparisons is that some units can cold fix on the move in the woods while others just sit there, searching. Most seem to be able to track me once they acquire a fix, which is a notable improvement from my earliest experiences.

If I sit in one place long enough, they all eventually narrow my location to within ten or so feet, given enough satellites plus WAAS reception. This is most noticable with elevation, which can take quite awhile to match a known height.

I've mostly used a PN60 and an Oregon 450 lately. The Oregon might have a sensitivity edge, plus the larger display. They're both far better than my eTrex Legend CX (except in battery life).

Cheers,

Rick

Mike W
(skopeo) - F

Locale: British Columbia
Most accurate handheld GPS? on 09/07/2011 01:04:48 MDT Print View

Most accurate for what?

I agree that the ability for a GPS to acquire and hold a signal under tough conditions is the most important feature to look for in a GPS. Accuracy is secondary in my opinion.

As for positional accuracy, I have run tests with several of my units (Garmin and Magellan) by placing them on a survey control monument and they all came up with coordinates that were within a metre of the published coordinates. I let the GPS "average" hundreds of coordinates over a 15-20 min period to get my final coords. That's pretty accurate, however I had a completely open sky view and I would also expect to get a totally different result if I re-ran the test a few weeks later as atmospheric disturbances and sunspot activity will effect the accuracy.

The newest isn't necessarily the greatest in my experience. The GPS I consider my most accurate handheld unit has a Sirf Star receiver and was used in certain Garmin models a few years back. It produced cleaner tracks (fewer spikes) and the trip data was far more accurate than my newer models which seem to have trouble calculating the distance travelled when I'm moving very slowly. The old Sirf Star receiver didn't have this problem. That said, I don't carry the Sirf Star GPS because it's heavier than my other GPS's and extreme accuracy isn't really required for my route finding.

So if you can find a new GPS that has a Sirf Star receiver, buy it. However I'm not aware of a handheld that uses that chipset in the newer GPS's as most manufacturers are using generic chipsets to reduce costs.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Most accurate handheld GPS? on 09/07/2011 21:14:10 MDT Print View

"Most accurate for what? "

I agree.

Most GPS users could not define GPS accuracy if it bit them on the butt.

To many GPS users, the ability to lock in signals in difficult view of the sky situations is very important.

To some GPS users, position repeatability is important.

Raw position accuracy is less important to many GPS users, but this is what surveyors want.

To get really good position accuracy, you need a professional receiver with some sort of atomic clock and a choke ring antenna. Right away we are talking about many thousands of bucks.

--B.G.--