Oregon 400T Accuracy

[+16:9]

I am new to geocaching and a new owner of a very nice Oregon 400t. I was wondering which GPS accuracy you manage to get with such unit. Is 30ft OK or should I expect something smaller? Should it change when using WAAS?

 

Thanks,

 

Christophe

[+Ladybug Kids]

I am new to geocaching and a new owner of a very nice Oregon 400t. I was wondering which GPS accuracy you manage to get with such unit. Is 30ft OK or should I expect something smaller? Should it change when using WAAS?

 

Thanks,

 

Christophe

I've seen "accuracies" of as good as 3 m/10 ft and as "poor" as 20 m/66 ft, depending on how many satellites my Oregon 300 is "seeing." I haven't seen any correlation between accuracy and WAAS, but I rarely get WAAS up here above 61° N.

[+twolpert]

WAAS likely won't help much. The reported accuracy depends mostly on the geometry of satellites overhead at that particular time and place. WAAS provides corrections for second-order effects like ionspheric conditions.

 

Depending on where you are, you may also be affected by multi-path errors. This happens in areas near large buildings or high hills, under heavy foliage, and so forth. The satellite signals bounce off of nearby surfaces. The unit does not know that the signals have been reflected -- and wouldn't know how to compensate even if it did know. Most of the time, errors due to multi-path effects aren't even reflected in the reported accuracy.

[+Walts Hunting]

With the Oregon it is a good idea to turn off the WAAS. As it cycles through various attempts to find one (without success usually and if you are under more than one tree never) it actually gets worse. You will do better without it.

[+spyderskier]

Updating the software made a big difference in my 400t.

[cooperspak]

Which version of the software made a big difference? I just got a 400t with version 3.20, and it seems to be working fine. But I'm always looking for something better, at least with technology.

[+spyderskier]

I also am running 3.2 and for the most part happy with it.

[+TEAM HARTSOCK]

I held one of these in my hands for the first time today at a store....

 

my 60CSx knew it the minute I walked in the door and isn't speaking to me right now.

[+burtsbodgers]

I held one of these in my hands for the first time today at a store....

 

my 60CSx knew it the minute I walked in the door and isn't speaking to me right now.

Its an omen but its a great unit

[+Rockin Roddy]

With the Oregon it is a good idea to turn off the WAAS. As it cycles through various attempts to find one (without success usually and if you are under more than one tree never) it actually gets worse. You will do better without it.

 

What? While my 300 didn't lock waas more than a few rimes, it still workd and I never saw it make things worse. If this is the case, why pay for something you can't use?

[ZeMartelo]

With the Oregon it is a good idea to turn off the WAAS. As it cycles through various attempts to find one (without success usually and if you are under more than one tree never) it actually gets worse. You will do better without it.

 

What? While my 300 didn't lock waas more than a few rimes, it still workd and I never saw it make things worse. If this is the case, why pay for something you can't use?

 

I have also noticed that since i've got the Oregon 550 it has not locked into WAAS at all, while the Colorado had no problems. I see the sat 51 bar go all the way up to the top but it never turns green.

Maybe a glitch with the software.... Garmin is due for a firmware upgrade anyway...

 

As anyone reported the WAAS acquisition problem yet?

[+Walts Hunting]

The WAAS acquisition problem is a very well known issue that has been reported since the Oregon series came out. Probably several thousand times. Forum discussions go on forever since every time someone buys one and it doesn't work they bring it up. It is well known and the general fix is turn it off. If you go to teh Oregon Wikispaces you can find the long version of why it makes it worse (they cycling problem, once it passes on the satellite closest it keeps working on others).

 

Two of my buddies have Colorado's and they get WAAS and don't have the arrow stick problem (another continuineing problem) The biggest part of the problem appears to be the antenna they changed to

 

The Oregon will eventually get WAAS if you don't go under any type of cover.

 

Garmin has tried to solve this problem since the start and while it might be a tiny bit better it still stinks.

 

Here is the bug report from Wikispaces and it is still current

 

1.WAAS performance is very poor. Setup>System>GPS Mode>WAAS causes the Oregon to add WAAS satellites to the locate list and cycle through WAAS satellites but the Oregon takes a very long time to lock onto WAAS satellites. In the northeast when the Oregon is powered on (cold-start) it will initially try to locate and acquire satellite 51. The Oregon will display a white bar for a minute or two and then start cycling through satellites in this order 51, 33, 48, 35, 33, 34, 35, 36, 47, 48, 51. Eventually the Oregon may achieve WAAS lock but it can take 30 minutes or longer even if there is a clear view of the WAAS satellite. If the Oregon is power cycled (warm-start) the white bar for satellite 51 will display, drop and then come back again and finally lock as a green -- this takes about 4 minutes, whereas the 60csx lock within seconds under the same conditions. May have been some minor improvement in acquiring lock with open view of sky in 2.93, but Oregon still quickly loses WAAS under cover. (2.98)

[+Rockin Roddy]

That's too bad. I'm glad to report that DeLorme (or at least MY DeLorme) locks waas (even my new one which doesn't as often) and this never makes the situation worse. I hope Garmin does find the fix....

[Grasscatcher]

Me thinks too many people are concerned with pictures not acual GPS accuracy.........navigate to a Benchmark with known and "adjusted" (not scaled) coordinates. Those coordinates are established closer than any consumer grade unit can calculate.

 

After NUMEROUS BM (with adjusted coordinates) checks, I have YET to do so and have my unit tell me that I am off more than 1-2 meters. (I use UTM)......whether or not it says I have a WAAS lock or can see the "D"s on the satellite bars, and regardless what the EPE guess is.

 

EPE is a calculated guesstimate, swag, unreliable comparison even within the same brand. There is absolutely no direct connection to accuracy.

 

If WAAS is available in your area, set your unit to receive it and forget it.

 

Determining the accuracy of your unit using "Cache" coordinates is impossible.

[+victorymike]

Don't rely too heavily on Estimated Position Error. It is, well...estimated.

 

The answer to your question is that your Colorado 400t is proven to work accurately enough to find thousands, if not tens of thousands, of geocaches all over the world...SO FAR (just a guess...there are a lot of geocachers using 400t's to seek out geocaches). Of course you could use it to seek out all 939,998 caches in the world (that is the current number of caches listed on gc.com's home page, as of this typing).

 

Remember that you are seekign out a specific point on the Earth that was posted by somebody else. So the EPE is compounded. The placer's error AND your error. As a long time geocache seeker I know that I start looking for landmarks once I approach within 300 feet of a cache, trying to guess where the cache would be hidden. Ditto as I approach closer, 200 feet, and closer, 100 feet. By the time I hit 50 feet away I usually have the hiding spot pegged. But there are days when the satellites aren't aligned (more specifically when you are using a totally different set of satellites than the placer) and maybe your gps is using one with a bad health rating (bad health rating is a real thing). Then you have to expand your search radius. To me, anything found more than 50 feet off would be an indication of a questionable hiding coordinate. Please note that I arbitrarily picked 50 feet. For those caches I like to take my own GPS coordinate and mention it to the cache owner, should they be so inclined to change it.

[+smstext]

the latest firmware for my etrek h seems to lock on to waas in minutes, perhaps garmin should look into which order the etrek h finds the waas and tell the oregon to do the same.

[+Walts Hunting]

The problem is the ceramic patch antenna. Not soft or firm ware.

[+twolpert]

The problem is the ceramic patch antenna. Not soft or firm ware.

That's not entirely true. The DeLorme PN-40 uses the same chipset and a similar patch antenna. Originally, the device obtained and used WAAS corrections very rarely unless you were located far enough south for the WAAS satellites (which are in equatorial orbit) to be well above your local horizon. Eventually DeLorme shipped a chipset firmware update which much improved the situation. Mind you, it is still much worse than my Garmin Colorado, which uses WAAS corrections all the time. Nevertheless, the problem was amenable to a (chipset) firmware correction. I would imagine that the same is true of the OR.

 

That said, WAAS corrects for second order effects like ionospheric disturbances. Satellite geometry is still the biggest factor in accuracy at any given time and place.

[+Maingray]

What twolpert said.

 

WAAS is sometimes helpful on my OR, sometimes not.

 

To the OP, 30 feet is on the high side. I can usually expect 5-20 feet EPE where I am (NC, USA). All depends on the satellite geometry.

[Grasscatcher]

The problem is the ceramic patch antenna. Not soft or firm ware.

That's not entirely true. The DeLorme PN-40 uses the same chipset and a similar patch antenna. Originally, the device obtained and used WAAS corrections very rarely unless you were located far enough south for the WAAS satellites (which are in equatorial orbit) to be well above your local horizon. Eventually DeLorme shipped a chipset firmware update which much improved the situation. Mind you, it is still much worse than my Garmin Colorado, which uses WAAS corrections all the time. Nevertheless, the problem was amenable to a (chipset) firmware correction. I would imagine that the same is true of the OR.

 

That said, WAAS corrects for second order effects like ionospheric disturbances. Satellite geometry is still the biggest factor in accuracy at any given time and place.

 

Just to be clear, these comments refer to a Garmin Oregon 550t.

 

Is it software/firmware? .........I don't know.

 

Is it senstivity to multipath error?.....I don't know.

 

Is it antenna?..............I don't know.

 

Is it Garmin vs DeLorme?..........I don't know.

 

HOWEVER, BOTH units and COMPANIES have REAL problems.

 

Here are my personal experiences and opinions. I enjoy Hiking, ATVing, Snowmobiling, and for the past 15+ years (remember Selective Availability?) I have GPS'd and mapped almost every trail I have traveled.

That equates to several thousand miles under almost every condition. Thru 7 GPSs I have evolved to using a Garmin Map76CSx. Why? Because that is what produces the best quality tracks overall, under all conditions. So, yes, I am 125% a Garmin fan (read on) because, ignoring all the Hype and BS, that is what works to date.

 

And, since I am always open to something better, as soon as the PN-40 came out, I got one thru REI and tried it. Under wide open ideal conditions, it did OK, but as soon as conditions started to become marginal (read canopy or canyons) its tracklogging could not even repeat with itself. Multiple out and back hikes on a single track trail produced tracklogging variations of 100+ feet, same day, same conditions. That's only comaparing it to itself, not the 76CSx (which was "hands down " more consistent). Needless to say, I no longer own a PN-40.

 

Next in line is the Oregon 550t. I will start off by saying that if this unit is supposed to be Garmin's top of the line handheld, Garmin has problems. Screen visibility in sunlight ( like a cheap camera LCD) and WAAS reception both suck! Everything else is dumbutt simple.

 

I like not having to carry a separate camera because the auto geotagging is great.( Also, the pics are surprisingly good) However, NOW I would have to carry a separate GPS if I wanted accurately logged trails. So, what have I gained? NADA.........

 

Here's a non-scientific, real world experiment. A 5 mile narrow single track loop trail in deep canyon country.

 

First Trip: carried 2 GPSs

Map 76CSx on right shoulder with X ant on top of backpack, Tracklogging Auto, More often logging interval, WAAS ON.

Oregon 550t on left shoulder Logging settings same (as 76) but WAAS OFF.

Trip produced 3 tracks, 76 CSxActive Log, 76CSx saved track (500 tps) and 550t track

 

Second Trip: carried 3 GPSs.....same single track trail as before.

Map 76 CSx on right shoulder, without X ant, same logging settings as before, and WAAS ON

Oregon 550t on left shoulder, same logging settings but with WAAS ON

Added: Map 76CS (non x-older non high sensitivity chip) hooked to X ant. GPS in pack and X ant on top of pack.

Trip produced 4 tracks, CSx active log, CSx saved, CS active log, and 550t track.

 

End results? The Oregon produced the two "stand out sorriest" of all seven tracks. Under Ideal conditions, all seven tracks are acceptable but, as soon as conditions deteriorate, the Oregon falls on it's face, to varying degrees. Between trips, it remembered the "areas" that it didn't like, and really did think that it was "off over there" on the other trip........somewhere.......but couldn't remember exactly how far within 50-100+ feet in the "bad areas"....while the 76CSx trudged consistently and accurately along.

 

My overall conclusion is that both Garmin & Delorme have spent too much time concentrating on "games" and not enough on GPS accuracy and capabilities. Neither of their latest units are serious tools....just bad jokes.

[Grasscatcher]

With the new 2.6 upgrade for the 550t, Garmin GREATLY improved the tracklogging accuracy issues.

 

I said I didn't know what the problem was..........apparently they DID know..... and did something about it!

 

Must have been in the "improved along road routing performance" part of the update.