What's the lowest feet accuracy you have had with your GPS?

[lackdog]

I'm curious to see what's the lowest accuracy you have seen with your GPS in feet. I'm not talking like one time it hit 4 foot of accuracy I'm talking more of the lines of sustained lowest accuracy. Like with my Garmin GPS V I usually get about 16 feet of accuracy steady.

[azog]

My Legend usually settles in around 22 feet.

 

----------

Do not answer a fool according to his folly, lest you be also be like him.

[+fizzymagic]

This is not a terribly useful subject since the so-called "accuracy" reading is not in fact a measurement of accuracy.

 

If you are interested in the actual accuracy of your device, find a nearby triangulation marker and use it to calibrate your actual error. Otherwise, it's best to mostly ignore the accuracy reading of your GPS.

[+briansnat]

I usually get between 18-26 feet with my Legend. I think I recall getting 12 a few times. I know this isn't a good measure of accuracy, but if I see accurate to 70 feet, or 120 feet, I'll hesitate to post those coordinates for my cache.

 

"It has been my experience that folks who have no vices have very few virtues" - Abraham Lincoln

[+Team Golden]

I would say my map76s usually is around 15-25 ft.

[Techneaux]

Usually about 16 feet here, with my Legend.

[+EraSeek]

As Fizzymagic says- ''This is not a terribly useful subject since the so-called "accuracy" reading is not in fact a measurement of accuracy.''

 

However, that being said, I have had a good solid 6' reading with my Map76 while driving down I-5 in Seattle with WAAS enabled.

 

[+Graveseeker]

I found the following statement interesting:

 

"If you are interested in the actual accuracy of your device, find a nearby triangulation marker and use it to calibrate your actual error. Otherwise, it's best to mostly ignore the accuracy reading of your GPS."

 

That raises the question as to whether GPSRs can, in fact, be calibrated (more accurately - corrected)? If we do some benchmarking, will we find a consistent N/S and E/W error that we can reliably crank in for correction? For example, if we search for 29 55.9371N by 95 55.823W, could we reliably correct to 29 55.9371N by 95 55.820W (given that +1 and -2 was our predetermined correction factors)?

 

Good Hunting! -- Graveseeker

[lackdog]

quote:

---

Originally posted by fizzymagic:

This is not a terribly useful subject since the so-called "accuracy" reading is not in fact a measurement of accuracy.

 

If you are interested in the actual accuracy of your device, find a nearby triangulation marker and use it to calibrate your actual error. Otherwise, it's best to mostly ignore the accuracy reading of your GPS.

---

 

Well the question I asked wasn't about how "on" your GPS is to a triangulation marker. I just simply was wondering what type of accuracy in feet other peoples GPS reported to them. The reason I say "GPS accuracy" is because thats the way my Garmin GPS V states it.

[+Cachetrotters]

Not having had the chance to record over a surveyed marker(a measure of absolute accuracy), I can only report the accuracy of positions recorded based on previously recorded positions(a measure of relative accuracy and precision).

 

As such, both my Merigreen and ST Pro regularly display +/- 1 digit of precision(mm.mmm), WAAS on, under static conditions with a good view of the sky(high desert) and less than 1 meter when using SA Watch.

 

Of course, this in no way indicates how they perform "on-the-move" or in heavy cover, but it is a fair indication of a receiver's potential.

 

don

[+Cachetrotters]

QUOTE]

 

Well the question I asked wasn't about how "on" your GPS is to a triangulation marker. I just simply was wondering what type of accuracy in feet other peoples GPS reported to them. The reason I say "GPS accuracy" is because thats the way my Garmin GPS V states it.

 

I would not think the accuracy statement by Garmin or Magellan nor any other mfg. is derrived by what is reported on the EPE display.

 

I don't know how the GPSr EPE is calculated but I would hope that the mfg. spec is arrived at by a more robust method.

 

don

[+Arpy]

My Legend averages about 12 feet.

[shrekTBA]

Vista- 16ft on average. Yellow- 22ft, Legend- 18

 

It's not a sport unless there is something dead in the back of the truck when you get home.

[Kerry.]

quote:

---

Originally posted by graveseeker:

.... That raises the question as to whether GPSRs can, in fact, be calibrated (more accurately - corrected)? If we do some benchmarking, will we find a consistent N/S and E/W error that we can reliably crank in for correction? For example, if we search for 29 55.9371N by 95 55.823W, could we reliably correct to 29 55.9371N by 95 55.820W (given that +1 and -2 was our predetermined correction factors)?

---

 

NO, calibration in pure GPS accuracy terms isn't an option. Some of the older units had what was termed a PCF (Position Correction Factor) but that was more to do with correcting for datum issues as they had no datum option (permanent WGS84).

 

Cheers, Kerry.

 

I never get lost everybody keeps telling me where to go

[Team Dragon]

I find the accuracy highly useful but that may be because I have cached in a variety of environments. I've noticed a difference in accuracy in different locations that most people haven't had to deal with and it certainly helps to know when I need to look within 150 feet of ground zero rather than 50.

[+cachew nut]

Error would probably be a better term to use.

[lackdog]

Some of you are analyzing my question a little bit to deep. I should stated my question like this.

 

On your GPS display under "GPS Accuracy" (on garmin models), What is usually your normal "GPS accuracy". MIne for instance is usually about 16ft.

 

Simple.

[+MedicP1]

My MAG 315 routinely gets a reading of 3 M. and have seen it go as low as 2 M. on frequent occassions(mostly while driving for the 2 M.).

 

GPSr's...A step in the right direction!

[dsandbro]

Since different manufacturers will use different algorithms to estimate positional accuracy, any number displayed must be taken with a healthy dose of salt. The EPE in most cases though is the 95% standard error.

 

As for me: Garmin III - 2 feet lasted about 3 minutes then went back up to 8 feet on a geocache search.

 

Trimble Pro-XRS = .01 meter for two hours (a really good day mapping!)

 

Friends don't let Friends geocache drunk.

[+Team Finn]

usually has a stated accuracy of about 13-15ft.

 

Me ambivalent? Well..... yes and no.

[+Gloom]

my 315 has settled on 6ft EPE quite a few times. In fact it does it so often I'm no longer surprised when it does it. On the other hand I'm also no longer surprised when it settles on 125+ ft EPE.

 

----

Duct tape is like the Force. It has a light side and a dark side, and it holds the universe together.

[Goat6500]

The lowest I had ever gotten was 6 meters on my Extrex before last summer. But as I was climbing up Mount Shasta(14,000 feet) in June, I suddenly noticed I was getting 4 meters all day long. Anyone else noticed a significant increase in accuracy at high altitudes?

[+roasteroo]

I look at EPE this way. It is the gps telling you how confident it is in telling you where you are. I looked for a cache in a valley yesterday and only got like 16 ft at the lowest,36 most of the time. There was not that much tree cover, but the horizon is so far out of view. 3-4 sats in view. There was deep snowand I could not find it. Im going back and I know when I do find it i was standing within the epe of my first GZ.

When I hike to a place on top of a mountain it can see all of the sats and is more confident in its readings. EPE of >7ft(approx 2m) are expected. This is when you look at the sat screen and youve locked every one on it. 12 in this case.

To me the benchmark thing can be decieving. With datum conversions and every thing else. I wouldnt bank my gps's acuraccy on a benchmark until I new the Benchmark's Vert and Horizantal Order. Still you would have to visit the benchmark on the different occations to see if it gives you the same reading on top of the smae bench mark 3 times. Ill stick with EPE.

[dsandbro]

quote:

---

Originally posted by Goat6500:

The lowest I had ever gotten was 6 meters on my Extrex before last summer. But as I was climbing up Mount Shasta(14,000 feet) in June, I suddenly noticed I was getting 4 meters all day long. Anyone else noticed a significant increase in accuracy at high altitudes?

---

 

Higher elevations means fewer terrain obstructions to the horizon so you will probably receive more satellites. Also the signal travels through less atmosphere so less distortion.

 

Friends don't let Friends geocache drunk.

[+Faderaven]

...while driving...in the rain today. Otherwise usually 6 - 8 meters. That last update from Garmin was a winner!

 

Let my heart be still a moment and this mystery explore

[+evergreenhiker!]

My etrex summit usually homes in around 18-22 feet. One cache in Eastern Washington had me at 1.5 feet sustained, but the terrain was treeless.

[+SteveL]

It was, however, sitting in a surveyors tripod, on a hill, with excellent horizons, WAAS on, 10 sats locked on, with both WAAS birds (35 and 47), light breeze, positive thoughts, etc. I have seen it down to 5' before, but that was after I sacrificed 3 old GPS’s and a compass to appease the GPS Gods. Oooommmmmmmmmmm……………….

 

The Venture that thinks it's a Leica

 

SteveL

 

Wherever you go, there you are.

[+Rusty & Libby]

My Sportrak Pro is normally at 13' and I find that WAAS is greatly overated. My old Mag315 is every bit as accurate (according to the EPE) without the bells & whistles.

 

Rusty...

 

--------------------------------------------------

Friends don't let friends cache locationless!

 

Rusty & Libby's Geocache Page

Michigan Geocaching Organization

[+Groundhound]

Holding my Sportrak Pro over a nearby benchmark it settled in at a distance from waypoint reading of 6'. Didn't look at the EPE so I don't know what it was reading.

[Team GPS]

On average, around 15 feet. The best I've had was at 5 feeting with my GPS V.

 

Mike (BrushFire)

Garmin GPS V

[+Freelens&Mosie]

My wife and I were searching for a cache in a local nature park. She had the GPS and was walking back and forth on the raised boardwalk as I was scouring the terrain for a likely hiding place. I looked back and she was on her knees bringing the GPS from head high to the deck of the boardwalk repeatedly. She finally said "It has to be under here because when I get close to the ground it reads 0 feet." I looked under the boardwalk and sure enough there it was. Now try to explain to someone who has had that experience , that the GPS is not a cache magnetometer.

 

The early bird may get the worm, but the second mouse gets the cheese.

[+Cachier]

quote:

---

Originally posted by freelens/mosie:

My wife and I were searching for a cache in a local nature park. She had the GPS and was walking back and forth on the raised boardwalk as I was scouring the terrain for a likely hiding place. I looked back and she was on her knees bringing the GPS from head high to the deck of the boardwalk repeatedly. She finally said "It has to be under here because when I get close to the ground it reads 0 feet." I looked under the boardwalk and sure enough there it was. Now try to explain to someone who has had that experience , that the GPS is not a cache magnetometer.

 

The early bird may get the worm, but the second mouse gets the cheese.

---

 

I had this same experience with a cache in Indiatlantic just last year using my yellow Etrex. Im sure the good results have to do with being in wide-open flat area. With the GPS flat on the boardwalk above the cache, the coordinates matched the published coords exactly.

 

"When you find it, its always in the last place you look."

[+Team GPSaxophone]

My lowest accuracy was about 276 feet, my best was 8 feet. The average best I get on my Venture is 14 feet.

 

Lowest accuracy implies worst accuracy.

Highest or best would better describe what you are looking for.

[+Zinnware]

Highgear has a Garmin eTrex Legend I have an eTrex Vista. After a recent software patch download from Garmin on 11/25/2002 we both consitently get 8 feet accuracy in open or close to open areas with WAAS enabled. My friend has recorded 5 feet accuracy. My best was 7 feet. In heavily wooded areas it is not uncommon to get 15-26 feet accuracy. Before the 11/25/2002 software patch my best accuracy was 13-14 feet. In a deep ravine or excessive dense tree cover I expect 23-56 feet accuracy.

[DARC]

I've gotten as low as 7 feet with the new Vista software (50)in clear sunny conditions during the autumn and summer. Winter overcast has seen my accuracy no better then 26 feet.

 

Prior to the new software (39), my best accuracy was never less then 14 feet. Under snow/rain conditions I never saw less then 24 feet.

[dweebe]

I've had my lowest accuracy down to 7 feet driving on I-55 in St. Louis just south of the A-B brewery.

[Micqn]

10 - 15 feet on my Magallen Gps 310, Sometimes closer. Sometimes WAY OFF but that was my fault.

See Daniels Park Cache

 

Happy. Hunting.

[AdirondakMud]

After marking a waypoint by holding the GPS next to a building in my back yard I transferred this way point to Expert GPS and brought up a new airiel photo. When zooming in to 200 FT on the map the waypoint was right on the building.