What is the most accurate GPS device on market?

[+SSUNBRN]

Hello!

 

I have been using my iPhone for caching and it works pretty well for the most part. I would like to supplement it with another GPS, specifically one that has REALLY good reception/accuracy.

 

Anyone care to give me some recommendations? No budget, don't care about any other features... just want an accurate device that will work well under tree-cover. I want to use the device when the iphone can't find GZ.

 

Thanks for any replies!

[+coggins]

Trimble GeoXH with a Zephyr for better than 20 cm accuracy.

[+Knight2000]

I am pretty sure there are more accuarate units than that. Check the units that have an atomic clock instead of quartz.

[+GerIRL]

Trimble GeoXH with a Zephyr for better than 20 cm accuracy.

That's fine and dandy if you have $7k+ to spend. I'm not sure what the OP meant with "No Budget". No budgetary constraints OR no budget, period. In any event, even with a $7k+ solution out in the woods that gets you to within 20 or 30cm's, it's not going to do you any good if the cache location was fixed under foliage with a bad GPSr or bad procedures and is 40ft off, or in the cache of GC1N26W 150ft+ off! My recommendation would be a Garmin Map60CSx for <$300 that NEVER loses lock under heavy foliage. FWIW, of course!

 

On the plus side, my company is purchasing not just 1, but 2 of those Trimble GeoXH units. So I anticipate "field testing" them when I place my future caches

[+Redwoods Mtn Biker]

Ditto on the 60CSx.

[GeoBobC]

What makes the Trimble so much more accurate? Do they post process the data? If so, how accurate is the Trimble under actual field condtions (before processing the data)?

[+Chrysalides]

I would like to supplement it with another GPS, specifically one that has REALLY good reception/accuracy.

Remember that the coordinates are only as good as the ones posted. And 0.001 minute of latitude is 6 ft, getting more precise than that is rather pointless. Unless you want to go around irritating all the cache owners in your area by correcting their coordinates to 4 decimal places each time you make a find, I'd say something with the precision of a 60CSX, eTrex HC / HCx series and equivalent would be good enough.

[+dukeofurl01]

In my area, you can tell who has an eTrex and who has a a 60CSx or Colorado or Oregon by how accurate the coordinates on their caches are.

 

The 60s and 76s are widely considered to be the most accurate for a "reasonable" amount of money.

[+jotne]

And on the 60/76 GPS you can do averaging to give a more accurate result. Using multiple reading over time to get it more accurate.

[+RRLover]

I would like to supplement it with another GPS, specifically one that has REALLY good reception/accuracy.

Remember that the coordinates are only as good as the ones posted. And 0.001 minute of latitude is 6 ft, getting more precise than that is rather pointless. Unless you want to go around irritating all the cache owners in your area by correcting their coordinates to 4 decimal places each time you make a find, I'd say something with the precision of a 60CSX, eTrex HC / HCx series and equivalent would be good enough.

If the cache owners get irritated, it may be because they feel inadequate. Different situations cause different feelings in different people.

Newer devices that can demonstrate useful acquisition to the 4th dec. should be encouraged; catering to lowest (common) denominators is not

a method towards increasing achievement, quite the opposite actually.

 

Norm

Edited April 18, 2009 by RRLover

[+bwmick]

I would like to supplement it with another GPS, specifically one that has REALLY good reception/accuracy.

Remember that the coordinates are only as good as the ones posted. And 0.001 minute of latitude is 6 ft, getting more precise than that is rather pointless. Unless you want to go around irritating all the cache owners in your area by correcting their coordinates to 4 decimal places each time you make a find, I'd say something with the precision of a 60CSX, eTrex HC / HCx series and equivalent would be good enough.

If the cache owners get irritated, it may be because they feel inadequate. Different situations cause different feelings in different people.

Newer devices that can demonstrate useful acquisition to the 4th dec. should be encouraged; catering to lowest (common) denominators is not

a method towards increasing achievement, quite the opposite actually.

 

Norm

 

I don't mind people correcting coords if they are way off, but if they are only a little bit I wonder why the user felt the need to correct. I always try to remember that the worst case scenerio is to add my error to your error and that number is as close as I should expect to get. It is great when the gps takes you right to the spot. on the days I don't zero in it doesn't mean my gps was way off, it may mean that our gps's were both off a little and created a discrepancy outside your comfort zone . even with WAAS i never expect my gps to get me closer than about 15 feet. lots of times it does, but it is never expected.

 

bwmick

[yogazoo]

What makes the Trimble so much more accurate? Do they post process the data? If so, how accurate is the Trimble under actual field condtions (before processing the data)?

 

I've seen a Trimble, Magellan 315, and a Garmin etrex side by side and there is actually NO difference in accuracy before you post-process the data. So if your talking about anything other than surveying and GIS data gathering the $7,000 is an absolute waste.

[+iamasmith]

Actually responding with a survey grade.. that's pandering to the question and you may as well have asked if they had access to military band and equipment in which case you could get down to 1cm.

 

Budget and practicality will probably mean a consumer grade.. 60CSx and if they ever get real honest performance (and it DOES perform well sometimes) possibly an Oregon - I know at the moment given the choice I would rather be stuck in the fog on a mountain with the 60CSx than the Oregon I have.

 

Regards,

 

-Andy

[+Rockin Roddy]

I see a lot of 60CSx answers here, but not any PN-40? The PN-40 has been shown to be just as or more accurate than the 60CSx, I have been thoroughly impressed with mine! The PN-40 also averages.

[+dukeofurl01]

The 60CSx also averages. Although I must admit that I don't really like that feature, it seems to cause more problems than it fixes.

[+Jamie Z]

So...

 

All these comments about some particular brand or model GPS being more accurate than others. Where is everyone getting the data? I'd like to see a link where a standardized comparison has been made.

 

Jamie

[stevensj2]

I don't think any unit can be more accurate (without post-processing) than another, inherently. The only thing affecting the unit itself will be its handling of WAAS and overall ability to get and hold a lock, which does differ from unit to unit.

 

The satellites are sending out deliberately "inaccurate" signals, and no unit can be more accurate than the signals it is receiving.

 

We are limited by the satellites, not the units.

 

(Its similar to the megapixel myth in digital cameras, where the companies advertise more megapixels as producing better images for the internet. Image quality is limited by the DPI of the medium, not the MP of the camera. No one will ever push the limits of even a 6mp camera until printing 26" photos at 300dpi or larger.)

Edited April 19, 2009 by stevensj2

[+user13371]

See also:

 

http://en.wikipedia.org/wiki/Global_Positi...es_and_analysis

[+Rockin Roddy]

See also:

 

http://en.wikipedia.org/wiki/Global_Positi...es_and_analysis

 

I looked, but it's well over my head!

[dr_barger]

I've read in other forums where people have said, "You can't use a Nuvi to do Geocashing because it doesn't have the accuracy". It seems to me that the 205 has as good/better accuracy and locks on to satelites much quicker than my 5 year old Etrex.

 

Battery life and weather resistance would be a valid argument. But the technology of the satelite reception is probably state of the art for all the newer GPS units.

 

Garmin's software signal processing for the 60CSX probably optimizes the capabilities of the hardware. But I would think that Garmin would use the same software throughout their product line to get the maximum performance out of all their units.

 

This is pure speculation on my part. But I would buy a GPS for the features that I want and assume that the reception accuracy is there.

 

Don

[roybassist]

All these comments about some particular brand or model GPS being more accurate than others. Where is everyone getting the data? I'd like to see a link where a standardized comparison has been made.

I would like to see that, too; but I’ve never heard of one. I think most of the comments come from anecdotal evidence: people who have geocached with different units, and especially with companions who were using different units, and observed that over time one unit or another seems to get better results more often. It’s far from scientific, and eventually it probably becomes somewhat self-fulfilling. People tend to notice and place more weight on evidence that supports what they expect to find, even if they try not to.

 

In any case, certain units get a reputation from users for being reliably accurate and dependable. In a group of users as large as the one here, that is probably worth considering, regardless of how it developed.

 

Also, some units have experienced notable problems, such as the “drift” issue with certain eTrex and, IIRC, Colorado models. The 60/76 series have never, to my knowledge, exhibited that problem.

[yogazoo]

Jamie Z,

 

So I'll download the GPX tracklog from several units and throw them into Google Earth. One can definately see the difference and whether or not a particular unit is "accurate" or more "accurate" than another based on the comparison in the data details.

 

You're right in assuming there are limited accuracy data which are analyzed scientifically but anecdoatal data are as good as gold and easily discernable. That said, the 60CSX is the gold standard in excellent and reproducable results. If you need to see scientific, peer-reviewed findings you'll be looking a long time to come to the same conclusion you would using relatively rigerous and robust anecdotal data.

 

OR, how about this for scientific data: Lets say 8 out of 10 GPS users in this forum recommend the 60CSX for accurate positional data. Accounting for the probable Garmin bias present here (maybe 20%) you can still say that over half of actual GPS users recommend the 60CSX. The science of polling applies here and you should be able to come to a reasonable conclusion.

Edited April 20, 2009 by yogazoo

[+MrArlie]

Acruacy is a misnomer because the GPS does not have eyes. You have to find the container and sign the log yourself.

[+DyverDown]

Well, actually, if money is no object and finding caches the objective, then hire each of the cache owners your going to find and they will probably be the most accurate (or potentially I guess the last finders of each cache would be best).

 

If your planning on doing a day of caching you'll need a fleet of limos, catering, might want a few pre-positioned portal potties..... the logistics......

 

Acruacy is a misnomer because the GPS does not have eyes. You have to find the container and sign the log yourself.