Odometer Error - Oregon 450

[MtnHermit]

So I took my new OR 450 out for a spin yesterday to create a trail tracklog. I clipped the OR to one shoulder strap of my pack and a CO to the other. Because I was at or above timberline most of the way, EPE was running a single digit most of the way.

 

The OR is running 3.80 and the CO 3.20.

 

Good News - Bad News.

The Good News: Both tracks matched near perfectly and measured 5.6 miles. Also, the elevations were +/- 20 ft of each other and agreed with known points.

 

The Bad News: The OR trip odometer appears to be off 20% on the low side.

 

 

 

Any thoughts or comments?

[+ecanderson]

Any thoughts or comments?

No very useful thoughts, yet, but a comment or two and a suggestion that might point to the nature of the problem. You're not the first to question the Oregon/Dakota trip odo readings:

 

http://forums.Groundspeak.com/GC/index.php?showtopic=258689

http://forums.Groundspeak.com/GC/index.php?showtopic=259663

 

Garmin knows they have had some issues in this area. Yet another tweak to the odo readings for your 450 was made in 3.74 beta. I don't recall whether anyone thought the result to be better, worse, or the same. Also can't be sure that the beta tweak made it into 3.80, but most often the firmware doesn't change a lot from the last beta to the release code.

 

Not having played with that feature in a side-by-side test, I can't confirm your readings -- only that I've seen even bigger differences reported in the threads above.

 

Suggestion: try a straight line test (just turn 'em both on and blast down a straight highway) to see what shows up. Wild guess -- they're trying to interpolate between track points - a truly impossible task to get right on the money - knowing full well that it's rarely a straight line between two points on what appears to be a curve (unless you're apexing them all in a race car!) - and they've somehow botched the calculations. A straight line test that shows good results might confirm this.

Edited September 13, 2010 by ecanderson

[+g-o-cashers]

Yep. Similar problems on the 62 and all of the Cartesio based units. Garmin has been releasing software improvements but I'll have to say not much has changed.

 

You'll see it if you are moving slower than 2mph or stopping frequently especially under tree cover. The Trip Odometer (and associated fields like stopped time) are usually off by 10-30% sometimes as much as 50% if you are really moving slowly.

[+bazzer2005]

Hi MtnHermit.

 

Have you got the latest software for the 450? It's worth checking as the latest release from Garmin included the following:-

 

"•Improved accuracy of trip odometer."

 

Mine was reading low as well, but seems much more accurate now.

 

Note - Although the documentation says version 3,9, when I updated last week, it said version 3.8, but included all the fixes. See the following link for more info. http://garminoregon.wikispaces.com/Versions#x=-Detailed Version History-Software 3.90

 

Regards Bazzer2005

[+ecanderson]

Hi MtnHermit.

 

Have you got the latest software for the 450?

Yes, he's running 3.80.

Note - Although the documentation says version 3,9

Don't confuse the firmware levels for the x00 version Oregons with the x50 versions. The most recent for x00 is 3.90, the most recent for the x50 is 3.80. Totally different firmware, and the similarity in numbers isn't relevant.

[+coggins]

Hi MtnHermit.

 

Have you got the latest software for the 450? It's worth checking as the latest release from Garmin included the following:-

 

"•Improved accuracy of trip odometer."

 

Mine was reading low as well, but seems much more accurate now.

 

Note - Although the documentation says version 3,9, when I updated last week, it said version 3.8, but included all the fixes. See the following link for more info. http://garminoregon.wikispaces.com/Versions#x=-Detailed Version History-Software 3.90

 

Regards Bazzer2005

Those links are for the x00 Oregon, you would want the x50 software here: LINK

[flyjazz]

Could it be that it's the Colorado that is off? It would seem to me that the Oregon is a newer and superior unit.

[+fegan]

Could it be that it's the Colorado that is off? It would seem to me that the Oregon is a newer and superior unit.

 

Newer - yes, I'll agree with that 100% since the Colorado is a discontinued model

 

Superior - that's open for debate...if my Colorado 400t died today I would buy another Colorado 400 before I went for any Oregon/Dakota

 

YMMV

[MtnHermit]

Could it be that it's the Colorado that is off? It would seem to me that the Oregon is a newer and superior unit.

From my unedited OP.

Both tracks matched near perfectly and measured 5.6 miles.

We have three numbers in agreement and one out of whack. Why do you believe the OR odometer is correct?

[flyjazz]

Could it be that it's the Colorado that is off? It would seem to me that the Oregon is a newer and superior unit.

From my unedited OP.

Both tracks matched near perfectly and measured 5.6 miles.

We have three numbers in agreement and one out of whack. Why do you believe the OR odometer is correct?

 

Had to read your post again,this time a little closer. Indeed,that is odd!

[MtnHermit]

Suggestion: try a straight line test (just turn 'em both on and blast down a straight highway) to see what shows up.

Going in a straight line is really foreign to my personalty. Just the thought gives me the shivers.

 

Wild guess -- they're trying to interpolate between track points - a truly impossible task to get right on the money - knowing full well that it's rarely a straight line between two points on what appears to be a curve (unless you're apexing them all in a race car!) - and they've somehow botched the calculations. A straight line test that shows good results might confirm this.

Interpolate not. I see the calculation as a giant spreadsheet, really no different than a track table. Calculating between two Lat long points is a very known algorithm, so simple sum those distances and round for the displayed value. Internally the GPS must have and hold many more values than we see in a track log, but hey who said this was easy.

 

Thanks for the comments.

[MtnHermit]

Yep. Similar problems on the 62 and all of the Cartesio based units. Garmin has been releasing software improvements but I'll have to say not much has changed.

 

You'll see it if you are moving slower than 2mph or stopping frequently especially under tree cover. The Trip Odometer (and associated fields like stopped time) are usually off by 10-30% sometimes as much as 50% if you are really moving slowly.

Well I'm pleased the track is accurate. However it's curious that the distance would error on the low side since it's primarily a vanity measurement. If Garmin were to error on the high side they'd have many fewer complaints.

 

I have a Nuvi Cartesio unit so when I get a chance I'll do a 4-way comparison, adding an eTrex.

[+ecanderson]

Suggestion: try a straight line test (just turn 'em both on and blast down a straight highway) to see what shows up.

Going in a straight line is really foreign to my personalty. Just the thought gives me the shivers.

Yeah, but still. Ripping up and down 24 a couple of times might turn out be illuminating for all of us. I might see what my old Summit HC looks like against my Oregon 450 on a run, too.

[+dfx]

the last comparison odometer vs tracklog i did was from a bike ride this weekend. both odometer and tracklog showed 14.0 km. this was mostly going straight, except for the cache hunts along the way.

[+OldA'sFan]

Yep. Similar problems on the 62 and all of the Cartesio based units. Garmin has been releasing software improvements but I'll have to say not much has changed.

 

You'll see it if you are moving slower than 2mph or stopping frequently especially under tree cover. The Trip Odometer (and associated fields like stopped time) are usually off by 10-30% sometimes as much as 50% if you are really moving slowly.

I have an Oregon 450 and recently updated to 3.74. Today I was on a 7 mile hike with at least half of it in deep forest. Never did loose sats., but accuracy dropped to 50 ft. or more quite often. The hike was a measured course. My trip od showed 4.9 miles, and my partners Vista HCx showed 6.9 miles. There were no breaks in the track, but my trip od was obviously way off. When I return home I'll update to 3.80 and see if that makes any differance.

OldA'sFan

[+g-o-cashers]

the last comparison odometer vs tracklog i did was from a bike ride this weekend. both odometer and tracklog showed 14.0 km. this was mostly going straight, except for the cache hunts along the way.

 

If you are driving in a car or biking (anything that gets you above 3mph) you'll see pretty consistent results especially if you aren't stopping.

[MtnHermit]

If you are driving in a car or biking (anything that gets you above 3mph) you'll see pretty consistent results especially if you aren't stopping.

Ah ha!!! I rarely get above 2mph, especially at 12,000'.

[John E Cache]

Some people get the fact that a GPS gives your approximate position to within 30 feet or so. They can see that their position changes when they stand still. What mystifies me is that these same people expect an accurate number when they add up a bunch of inaccurate positions to make an odometer. It ain't going to happen.

[+dfx]

Some people get the fact that a GPS gives your approximate position to within 30 feet or so. They can see that their position changes when they stand still. What mystifies me is that these same people expect an accurate number when they add up a bunch of inaccurate positions to make an odometer. It ain't going to happen.

what's so unrealistic about wanting to have an odometer that shows the same distance as the tracklog?

[+2Wheel'in]

Quite possible the way different receivers "interpret" the speed and stops. MooseMaMa and I did a 4.5 mile hike over varied/rough terrain, under heavy leaf cover. We each used a Garmin RINO 530HCx (SW Ver 2.50), and I also had my Oregon 450 (SW Ver 3.80) clipped to the shoulder strap of my CamelBak. The RINOs recorded distances were: her's 4.5 miles; my RINO 4.8 miles; and the Oregon 450 recorded 4.3 miles. Track logs were almost perfect overlays, with just slight differences over the entire hike. (The stated 4.5 distance was based upon published data for the trail we took...it is a close approximation, but not totally accurate). Anyway, the recorded distances are close enough for my use.

 

Bill

[+OldA'sFan]

So I took my new OR 450 out for a spin yesterday to create a trail tracklog. I clipped the OR to one shoulder strap of my pack and a CO to the other. Because I was at or above timberline most of the way, EPE was running a single digit most of the way.

 

The OR is running 3.80 and the CO 3.20.

 

Good News - Bad News.

The Good News: Both tracks matched near perfectly and measured 5.6 miles. Also, the elevations were +/- 20 ft of each other and agreed with known points.

 

The Bad News: The OR trip odometer appears to be off 20% on the low side.

 

 

 

Any thoughts or comments?

How do I determine the distance of a track on my Oregon 450.

OldA'sFan

[MtnHermit]

How do I determine the distance of a track on my Oregon 450.

OldA'sFan

You can't, AFAIK, inside your OR. But in Mapsource, click on the track line or name in the tab and a Track spreadsheet will appear. Look for the total length at the bottom.

[+2Wheel'in]

FWIW as a follow-up to my post #20. Took a short road trip for vehicle service this morning - Oregon 450 (ver 3.80) Track Log listed length of track at 8.3mi, Trip Odometer showed 8.35mi. Close enough for me.

 

Bill

[MtnHermit]

FWIW as a follow-up to my post #20. Took a short road trip for vehicle service this morning - Oregon 450 (ver 3.80) Track Log listed length of track at 8.3mi, Trip Odometer showed 8.35mi. Close enough for me.

Bill,

 

You're missing the key point, read post #16. So get off your duff and start walking and report back.

[+2Wheel'in]

FWIW as a follow-up to my post #20. Took a short road trip for vehicle service this morning - Oregon 450 (ver 3.80) Track Log listed length of track at 8.3mi, Trip Odometer showed 8.35mi. Close enough for me.

Bill,

 

You're missing the key point, read post #16. So get off your duff and start walking and report back.

 

.......and that's why I mentioned the "walking speed" in Post #20...obviously the slower speed causes

the/some error.

 

Bill

[+ecanderson]

.......and that's why I mentioned the "walking speed" in Post #20...obviously the slower speed causes

the/some error.

 

Bill

Yet to be demonstrated. Is the speed, stop/start, or changes in direction that make the biggest difference? To confirm, it seems we would need two straight line slow walks, one with and without start/stop activity.

[+Redwoods Mtn Biker]

How do I determine the distance of a track on my Oregon 450.

OldA'sFan

You can't, AFAIK, inside your OR. But in Mapsource, click on the track line or name in the tab and a Track spreadsheet will appear. Look for the total length at the bottom.

 

Mmm, don't have one with me right now, but try Track Manager > Current (or other) Track > View Map and I think you'll see the distance.

[+myotis]

Could it be that it's the Colorado that is off? It would seem to me that the Oregon is a newer and superior unit.

 

Newer - yes, I'll agree with that 100% since the Colorado is a discontinued model

 

Superior - that's open for debate...if my Colorado 400t died today I would buy another Colorado 400 before I went for any Oregon/Dakota

 

YMMV

 

I thought the same thing when my CO 400T died. I got a 550T and I was suprised I like it much better than the CO.

 

Fri and Sat I took a 260 mile train ride. Both times, my odometer was off less than .25 miles of the actual distance.

[+OldA'sFan]

How do I determine the distance of a track on my Oregon 450.

OldA'sFan

You can't, AFAIK, inside your OR. But in Mapsource, click on the track line or name in the tab and a Track spreadsheet will appear. Look for the total length at the bottom.

Thanks much for the info.

 

OldA'sFan

[+OldA'sFan]

How do I determine the distance of a track on my Oregon 450.

OldA'sFan

You can't, AFAIK, inside your OR. But in Mapsource, click on the track line or name in the tab and a Track spreadsheet will appear. Look for the total length at the bottom.

 

Mmm, don't have one with me right now, but try Track Manager > Current (or other) Track > View Map and I think you'll see the distance.

You are right on. Thanks much.

[MtnHermit]

Mmm, don't have one with me right now, but try Track Manager > Current (or other) Track > View Map and I think you'll see the distance.

Rich,

 

Thanks for that tip, easy to do and since the trip odo is off 20%+ below 3 mph, I'll be using that a lot.

[+Redwoods Mtn Biker]

Glad to help! Clearly these newer units can record accurate mileage. Hopefully Garmin will fix the odometer field to reflect it.

[MtnHermit]

Hopefully Garmin will fix the odometer field to reflect it.

I won't be holding my breath.

[MtnHermit]

When I started this thread my trip odometer was 20% lower than the tracklog. v3.80

 

A few weeks later Garmin introduced v3.90 firmware and the trip odometer was ~2% low.

 

I'm now running v4.50 (GPS v5.00) and the trip odometer is consistently high ~2-3% vs the tracklog distance.

 

I just came back from a day hike, the trip odometer showed 12.37 miles, the tracklog 12 miles.

 

While I'd prefer perfect, high errors inflate my ego.

[+mtnbikerik]

When I started this thread my trip odometer was 20% lower than the tracklog. v3.80

 

A few weeks later Garmin introduced v3.90 firmware and the trip odometer was ~2% low.

 

I'm now running v4.50 (GPS v5.00) and the trip odometer is consistently high ~2-3% vs the tracklog distance.

 

I just came back from a day hike, the trip odometer showed 12.37 miles, the tracklog 12 miles.

 

While I'd prefer perfect, high errors inflate my ego.

 

My 450 is running v5.5 & GPS ver 5.0.....have you tried this newer version? I'd be curious to know what you thought of it. I don't get too wrapped up in the mileage to worry about it as at the faster speeds it seems to be more accurate.....my Max Speed currently being 673mph.